Glossary · word list
English terms: History & Geography
1,152 words and terms, A–Z, from School Launch lessons. Each links to the lesson where it is taught.
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100th meridianEnglish
The line of longitude 100 degrees west. Roughly west of it, the plains usually get too little rain for farming without care.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.3 (grade 4)
The line of longitude 100 degrees west. Roughly west of it, the plains usually get too little rain for farming without care.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.3 (grade 4)
15-inch rain lineEnglish
The isohyet of about 15 inches (about 380–400 mm) a year, roughly the dry limit of dependable rain-fed farming in northern China; the Great Wall runs close to it for much of its length.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
The isohyet of about 15 inches (about 380–400 mm) a year, roughly the dry limit of dependable rain-fed farming in northern China; the Great Wall runs close to it for much of its length.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
38th parallelEnglish
The line of 38° north latitude, chosen by American officers in August 1945 as the dividing line between the Soviet and American zones of occupation in Korea.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
The line of 38° north latitude, chosen by American officers in August 1945 as the dividing line between the Soviet and American zones of occupation in Korea.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
49th parallelEnglish
The line of 49° north latitude. A long, straight part of the border between the United States and Canada follows it from Minnesota west to the Pacific.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.2 (grade 4)
The line of 49° north latitude. A long, straight part of the border between the United States and Canada follows it from Minnesota west to the Pacific.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.2 (grade 4)
A
absolute and relative locationEnglish
Absolute location is a position given by a precise reference system, such as latitude and longitude (Mainz: 50.0° N, 8.3° E). Relative location is a position described in relation to other places (“on the Rhine, opposite the mouth of the Main”).
Human Geography, Lesson 1.2 (grade 9–12)
Absolute location is a position given by a precise reference system, such as latitude and longitude (Mainz: 50.0° N, 8.3° E). Relative location is a position described in relation to other places (“on the Rhine, opposite the mouth of the Main”).
Human Geography, Lesson 1.2 (grade 9–12)
accretion and erosionEnglish
The gradual adding of land to one bank and wearing away of the other. Under U.S.–Mexico treaties, the border moves with the river when the change is gradual.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
The gradual adding of land to one bank and wearing away of the other. Under U.S.–Mexico treaties, the border moves with the river when the change is gradual.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
acropolisEnglish
Greek for “high city”: a fortified hilltop in or above a town, used as a refuge and holy place. The most famous is the Acropolis of Athens.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8) · Grade 6 Greek, Lesson 3.2 (grade 6)
Greek for “high city”: a fortified hilltop in or above a town, used as a refuge and holy place. The most famous is the Acropolis of Athens.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8) · Grade 6 Greek, Lesson 3.2 (grade 6)
active layerEnglish
The top layer of soil above permafrost that thaws each summer and freezes again each winter.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
The top layer of soil above permafrost that thaws each summer and freezes again each winter.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
adobeEnglish
Say it “uh-DOE-bee.” Mud mixed with straw, shaped into bricks and dried hard in the hot sun.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2)
Say it “uh-DOE-bee.” Mud mixed with straw, shaped into bricks and dried hard in the hot sun.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2)
aggregationEnglish
Combining data from smaller units into larger ones (households into tracts, counties into states). Aggregation simplifies, but it hides differences inside each unit.
Human Geography, Lesson 1.4 (grade 9–12)
Combining data from smaller units into larger ones (households into tracts, counties into states). Aggregation simplifies, but it hides differences inside each unit.
Human Geography, Lesson 1.4 (grade 9–12)
agricultural densityEnglish
The number of farmers per unit of arable land. A high figure usually means many small farms worked by hand; a low figure usually means machines and large farms.
Human Geography, Lesson 2.1 (grade 9–12)
The number of farmers per unit of arable land. A high figure usually means many small farms worked by hand; a low figure usually means machines and large farms.
Human Geography, Lesson 2.1 (grade 9–12)
agricultural hearthEnglish
A place where farming began independently, with its own set of domesticated plants and animals.
Human Geography, Lesson 6.1 (grade 9–12)
A place where farming began independently, with its own set of domesticated plants and animals.
Human Geography, Lesson 6.1 (grade 9–12)
agricultural intensificationEnglish
Getting more food from the same land by more labor, better tools, irrigation, fertilizer and new methods. Ester Boserup argued population growth drives it.
Human Geography, Lesson 2.3 (grade 9–12)
Getting more food from the same land by more labor, better tools, irrigation, fertilizer and new methods. Ester Boserup argued population growth drives it.
Human Geography, Lesson 2.3 (grade 9–12)
agricultureEnglish
Farming: growing crops and raising animals.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4)
Farming: growing crops and raising animals.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4)
aiming offEnglish
Aiming deliberately to one side of a target on a line feature, so that when you reach the line you know which way to turn.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8)
Aiming deliberately to one side of a target on a line feature, so that when you reach the line you know which way to turn.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8)
air draftEnglish
The height of a ship from the waterline to its highest point. A ship whose air draft is greater than a bridge’s clearance cannot pass under it.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
The height of a ship from the waterline to its highest point. A ship whose air draft is greater than a bridge’s clearance cannot pass under it.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
air routeEnglish
A regular path flown by aircraft between airports, shaped by distance, range, winds, weather, terrain and the places where planes can land and refuel.
Technology Overcoming Geography, Lesson 4.3 (grade 9–12)
A regular path flown by aircraft between airports, shaped by distance, range, winds, weather, terrain and the places where planes can land and refuel.
Technology Overcoming Geography, Lesson 4.3 (grade 9–12)
air-age globalismEnglish
The idea, popular in the 1940s, that airplanes had shrunk the world so that every region now touched every other and no nation could stand apart.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
The idea, popular in the 1940s, that airplanes had shrunk the world so that every region now touched every other and no nation could stand apart.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
alliance ringEnglish
The chain of American treaties around Eurasia built between 1949 and 1955: NATO, ANZUS, the treaties with Japan, the Philippines and South Korea, SEATO, and the Baghdad Pact (later CENTO), which the United States backed without formally joining.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
The chain of American treaties around Eurasia built between 1949 and 1955: NATO, ANZUS, the treaties with Japan, the Philippines and South Korea, SEATO, and the Baghdad Pact (later CENTO), which the United States backed without formally joining.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
alluvial fanEnglish
A fan-shaped spread of gravel and sand laid down where a mountain stream leaves its valley and slows; water often sinks into it and reappears as springs at its lower edge.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12)
A fan-shaped spread of gravel and sand laid down where a mountain stream leaves its valley and slows; water often sinks into it and reappears as springs at its lower edge.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12)
alluvial plainEnglish
A wide, flat land built of silt that a river has laid down in its floods.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
A wide, flat land built of silt that a river has laid down in its floods.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
AltiplanoEnglish
A high, cold plateau in the Andes of Peru and Bolivia, mostly about 3,600 to 4,000 m (12,000 to 13,000 ft) above the sea, holding Lake Titicaca.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
A high, cold plateau in the Andes of Peru and Bolivia, mostly about 3,600 to 4,000 m (12,000 to 13,000 ft) above the sea, holding Lake Titicaca.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
altitude zonesEnglish
Bands of climate on a mountainside, because the air grows cooler as you climb. In Latin America they are called tierra caliente (hot land), tierra templada (temperate land), tierra fría (cold land) and tierra helada (frozen land).
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
Bands of climate on a mountainside, because the air grows cooler as you climb. In Latin America they are called tierra caliente (hot land), tierra templada (temperate land), tierra fría (cold land) and tierra helada (frozen land).
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
amalgamation (patio process)English
A way of refining silver by grinding ore and mixing it with mercury and salt; the mercury bonds with the silver and is later driven off by heat. It made low-grade ore profitable.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.2 (grade 9–12)
A way of refining silver by grinding ore and mixing it with mercury and salt; the mercury bonds with the silver and is later driven off by heat. It made low-grade ore profitable.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.2 (grade 9–12)
Amazon BasinEnglish
All the land drained by the Amazon River and its tributaries, about 7 million km² (2.7 million sq mi), most of it covered by tropical rain forest.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
All the land drained by the Amazon River and its tributaries, about 7 million km² (2.7 million sq mi), most of it covered by tropical rain forest.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
American MediterraneanEnglish
Spykman’s name for the Gulf of Mexico, the Caribbean Sea and the lands around them, the part of the hemisphere the United States could most easily dominate.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
Spykman’s name for the Gulf of Mexico, the Caribbean Sea and the lands around them, the part of the hemisphere the United States could most easily dominate.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
amphibiousEnglish
Able to act both on land and at sea. Spykman said rimland states must be amphibious, defending themselves against land power from the interior and sea power from the oceans.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
Able to act both on land and at sea. Spykman said rimland states must be amphibious, defending themselves against land power from the interior and sea power from the oceans.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
anchor featureEnglish
An easy-to-remember shape or line, such as Florida or the Great Lakes, that you draw first and use to place everything else.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.2 (grade 4)
An easy-to-remember shape or line, such as Florida or the Great Lakes, that you draw first and use to place everything else.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.2 (grade 4)
annonaEnglish
Rome’s public grain supply, much of it shipped from Egypt, North Africa and Sicily to feed the city.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
Rome’s public grain supply, much of it shipped from Egypt, North Africa and Sicily to feed the city.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
annual temperature rangeEnglish
The difference between the average temperature of the warmest month and that of the coldest month.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.1 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
The difference between the average temperature of the warmest month and that of the coldest month.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.1 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
Antarctic CircleEnglish
The parallel of latitude about 66½° south. South of it the sun stays up all day for at least one day each summer.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
The parallel of latitude about 66½° south. South of it the sun stays up all day for at least one day each summer.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
Antarctic TreatyEnglish
The treaty signed in Washington on December 1, 1959, by twelve nations, which reserves the area south of 60°S for peaceful purposes and scientific research and freezes all territorial claims.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
The treaty signed in Washington on December 1, 1959, by twelve nations, which reserves the area south of 60°S for peaceful purposes and scientific research and freezes all territorial claims.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
antecedent and superimposed bordersEnglish
An antecedent border was drawn before many people settled the land; a superimposed border was imposed on peoples already living there, often by outside powers (such as many lines from the Berlin Conference).
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
An antecedent border was drawn before many people settled the land; a superimposed border was imposed on peoples already living there, often by outside powers (such as many lines from the Berlin Conference).
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
antecedent boundaryEnglish
A boundary drawn before the area was heavily settled, such as the 49th parallel between the western United States and Canada.
Human Geography, Lesson 5.2 (grade 9–12)
A boundary drawn before the area was heavily settled, such as the 49th parallel between the western United States and Canada.
Human Geography, Lesson 5.2 (grade 9–12)
antecedent, subsequent, superimposed, relicEnglish
A way of classifying borders by when they were drawn: before most people settled (antecedent), after settlement, following divisions among peoples (subsequent), by an outside power over existing peoples (superimposed), or a line that no longer works as a border but still shows on the land (relic).
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
A way of classifying borders by when they were drawn: before most people settled (antecedent), after settlement, following divisions among peoples (subsequent), by an outside power over existing peoples (superimposed), or a line that no longer works as a border but still shows on the land (relic).
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
antimeridianEnglish
The meridian exactly opposite a given meridian, 180° away on the other side of the globe. Where a dividing line is drawn around the world, it must be settled on both sides.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
The meridian exactly opposite a given meridian, 180° away on the other side of the globe. Where a dividing line is drawn around the world, it must be settled on both sides.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
ANZACEnglish
The Australian and New Zealand Army Corps, formed in Egypt in 1914 and landed at Gallipoli on 25 April 1915.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
The Australian and New Zealand Army Corps, formed in Egypt in 1914 and landed at Gallipoli on 25 April 1915.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
Appalachian MountainsEnglish
Old, low, rounded mountains in the eastern part of our country.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.1 (grade 2)
Old, low, rounded mountains in the eastern part of our country.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.1 (grade 2)
arbitrationEnglish
Settling a dispute by asking a neutral judge to decide, with both sides promising to accept the result. Britain’s King Edward VII arbitrated the Andes boundary in 1902.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
Settling a dispute by asking a neutral judge to decide, with both sides promising to accept the result. Britain’s King Edward VII arbitrated the Andes boundary in 1902.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
Arctic and Antarctic CirclesEnglish
The lines of latitude about 66.6° north and south. Poleward of them there is at least one day a year when the sun does not set and one when it does not rise.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.2 (grade 6)
The lines of latitude about 66.6° north and south. Poleward of them there is at least one day a year when the sun does not set and one when it does not rise.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.2 (grade 6)
arithmetic densityEnglish
The total number of people divided by the total land area, such as people per square kilometer or per square mile.
Human Geography, Lesson 2.1 (grade 9–12)
The total number of people divided by the total land area, such as people per square kilometer or per square mile.
Human Geography, Lesson 2.1 (grade 9–12)
arithmetic (linear) growthEnglish
Growth by a constant amount in each period, as 1, 2, 3, 4, 5. Malthus said food supply could at best grow this way.
Human Geography, Lesson 2.3 (grade 9–12)
Growth by a constant amount in each period, as 1, 2, 3, 4, 5. Malthus said food supply could at best grow this way.
Human Geography, Lesson 2.3 (grade 9–12)
armistice lineEnglish
A line where opposing armies agree to stop fighting, which may become a de facto border without a final peace treaty.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
A line where opposing armies agree to stop fighting, which may become a de facto border without a final peace treaty.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
army groupEnglish
A very large command made of several armies. Germany attacked with three: North (toward Leningrad), Center (toward Moscow) and South (toward Kyiv and Ukraine).
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
A very large command made of several armies. Germany attacked with three: North (toward Leningrad), Center (toward Moscow) and South (toward Kyiv and Ukraine).
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
arsenalEnglish
A state shipyard and armory. The Arsenal of Venice built and repaired the Republic’s galleys.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.1 (grade 8)
A state shipyard and armory. The Arsenal of Venice built and repaired the Republic’s galleys.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.1 (grade 8)
astronomical stationEnglish
A point where surveyors fixed latitude by observing stars, usually over many nights, to locate the parallel there.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
A point where surveyors fixed latitude by observing stars, usually over many nights, to locate the parallel there.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
Atlantic Coastal PlainEnglish
The low, flat land of sand, gravel and clay along the Atlantic coast, where rivers are wide, slow and often tidal.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
The low, flat land of sand, gravel and clay along the Atlantic coast, where rivers are wide, slow and often tidal.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
atomic clockEnglish
An extremely precise clock that keeps time by the vibrations of atoms. GPS satellites carry them so their signals are timed to billionths of a second.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8) · Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
An extremely precise clock that keeps time by the vibrations of atoms. GPS satellites carry them so their signals are timed to billionths of a second.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8) · Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
attack pointEnglish
An easy-to-find feature close to a control, from which you navigate carefully the last short distance.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
An easy-to-find feature close to a control, from which you navigate carefully the last short distance.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
attenuationEnglish
The gradual loss of signal strength along a cable, measured in decibels per kilometer (dB/km). Every 10 dB of loss cuts the power to one tenth.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
The gradual loss of signal strength along a cable, measured in decibels per kilometer (dB/km). Every 10 dB of loss cuts the power to one tenth.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
attributeEnglish
A piece of data attached to a map feature, such as a road’s name and speed limit or a house’s address and year built.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.4 (grade 8)
A piece of data attached to a map feature, such as a road’s name and speed limit or a house’s address and year built.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.4 (grade 8)
autarkyEnglish
A condition of no trade, in which a country produces everything it uses.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
A condition of no trade, in which a country produces everything it uses.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
azalaiEnglish
The great camel caravans that carried slabs of rock salt from the Saharan mines (Taghaza, later Taoudenni) south to Timbuktu.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
The great camel caravans that carried slabs of rock salt from the Saharan mines (Taghaza, later Taoudenni) south to Timbuktu.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
azimuthal equidistant projectionEnglish
A map projection centered on one point, on which distances and directions from that center are true. Centered on the North Pole, it shows the Arctic as the middle of the northern world.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
A map projection centered on one point, on which distances and directions from that center are true. Centered on the North Pole, it shows the Arctic as the middle of the northern world.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
azimuthal projectionEnglish
A projection drawn around one center point, on which directions from that center are true; in the equidistant form, distances from the center are true as well.
Geopolitics: The Great Ideas, Lesson 1.4 (grade 9–12)
A projection drawn around one center point, on which directions from that center are true; in the equidistant form, distances from the center are true as well.
Geopolitics: The Great Ideas, Lesson 1.4 (grade 9–12)
B
baby boomEnglish
A period of unusually high births, especially in the United States from 1946 through 1964, after the Depression and the Second World War.
Human Geography, Lesson 2.4 (grade 9–12)
A period of unusually high births, especially in the United States from 1946 through 1964, after the Depression and the Second World War.
Human Geography, Lesson 2.4 (grade 9–12)
back bearingEnglish
The direction straight back the way you came: your bearing plus or minus 180°.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.4 (grade 5) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.1 (grade 8) · Trigonometry, Lesson 8.2 (grade 11–12)
The direction straight back the way you came: your bearing plus or minus 180°.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.4 (grade 5) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.1 (grade 8) · Trigonometry, Lesson 8.2 (grade 11–12)
balance of powerEnglish
A situation in which no one state or bloc is strong enough to dominate the others, so each is checked by the rest. Spykman held that American safety depended on a balance in Eurasia.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
A situation in which no one state or bloc is strong enough to dominate the others, so each is checked by the rest. Spykman held that American safety depended on a balance in Eurasia.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
Balfour DeclarationEnglish
A letter of November 2, 1917, from British Foreign Secretary Arthur Balfour to Lord Rothschild stating British support for a Jewish national home in Palestine, while protecting the rights of the existing non-Jewish communities.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
A letter of November 2, 1917, from British Foreign Secretary Arthur Balfour to Lord Rothschild stating British support for a Jewish national home in Palestine, while protecting the rights of the existing non-Jewish communities.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
Baltic SeaEnglish
A shallow, brackish enclosed sea of northern Europe, bordered by nine countries and entered from the ocean only through the Danish Straits (or the Kiel Canal).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
A shallow, brackish enclosed sea of northern Europe, bordered by nine countries and entered from the ocean only through the Danish Straits (or the Kiel Canal).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
bambooEnglish
A very tall grass with a hard, hollow stem. Giant pandas eat it almost all day.
Grade 1 Geography: Maps and Journeys, Lesson 7.2 (grade 1)
A very tall grass with a hard, hollow stem. Giant pandas eat it almost all day.
Grade 1 Geography: Maps and Journeys, Lesson 7.2 (grade 1)
bancoEnglish
A piece of land cut off by a river’s sudden change of course and left on the “wrong” side of the new channel.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
A piece of land cut off by a river’s sudden change of course and left on the “wrong” side of the new channel.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
Banda IslandsEnglish
A cluster of tiny volcanic islands in the Banda Sea, south of Seram, which until the 1700s were the world’s only source of nutmeg and mace.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
A cluster of tiny volcanic islands in the Banda Sea, south of Seram, which until the 1700s were the world’s only source of nutmeg and mace.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
bargeEnglish
A long, flat-bottomed boat that carries heavy loads on rivers and canals.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.2 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 1.4 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8)
A long, flat-bottomed boat that carries heavy loads on rivers and canals.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.2 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 1.4 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8)
barrel (bbl)English
The standard unit for oil: 42 U.S. gallons, about 159 liters.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
The standard unit for oil: 42 U.S. gallons, about 159 liters.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
base tunnelEnglish
A tunnel dug through the bottom of a mountain range, close to the level of the valleys on each side, so trains need hardly climb at all.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12) · Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
A tunnel dug through the bottom of a mountain range, close to the level of the valleys on each side, so trains need hardly climb at all.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12) · Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
baseplate compassEnglish
A compass mounted on a clear, flat plate with a ruler and a direction-of-travel arrow, made for use on a map.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.4 (grade 5)
A compass mounted on a clear, flat plate with a ruler and a direction-of-travel arrow, made for use on a map.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.4 (grade 5)
basinEnglish
A broad, low area of land surrounded by higher ground, such as the Pannonian (Great Hungarian) Plain.
Geography and History: Why Borders Fall Where They Do, Lesson 2.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
A broad, low area of land surrounded by higher ground, such as the Pannonian (Great Hungarian) Plain.
Geography and History: Why Borders Fall Where They Do, Lesson 2.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
beachEnglish
The low edge of the coast covered with sand or small stones.
Grade 1 Geography: Maps and Journeys, Lesson 3.4 (grade 1)
The low edge of the coast covered with sand or small stones.
Grade 1 Geography: Maps and Journeys, Lesson 3.4 (grade 1)
beacon towerEnglish
A watchtower from which smoke by day or fire by night signaled the approach of raiders to the next tower and to the garrisons behind.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
A watchtower from which smoke by day or fire by night signaled the approach of raiders to the next tower and to the garrisons behind.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
before-and-after comparisonEnglish
A table or calculation showing time, distance, cost or capacity before a technology and after it, from reliable sources.
Technology Overcoming Geography, Lesson 5.5 (grade 9–12)
A table or calculation showing time, distance, cost or capacity before a technology and after it, from reliable sources.
Technology Overcoming Geography, Lesson 5.5 (grade 9–12)
belly cargoEnglish
Freight carried in the lower holds of passenger airliners, as opposed to dedicated freighter aircraft.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
Freight carried in the lower holds of passenger airliners, as opposed to dedicated freighter aircraft.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
beltwayEnglish
A limited-access highway that circles a city, linking its suburbs to one another without passing through downtown.
Human Geography, Lesson 7.4 (grade 9–12)
A limited-access highway that circles a city, linking its suburbs to one another without passing through downtown.
Human Geography, Lesson 7.4 (grade 9–12)
besetEnglish
Trapped in the ice and unable to move, as a ship can be when the pack closes around it.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
Trapped in the ice and unable to move, as a ship can be when the pack closes around it.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
bid-rent curveEnglish
A line showing how much each land user is willing to pay for land at each distance from the center; the highest bidder at each distance wins the land.
Human Geography, Lesson 7.3 (grade 9–12)
A line showing how much each land user is willing to pay for land at each distance from the center; the highest bidder at each distance wins the land.
Human Geography, Lesson 7.3 (grade 9–12)
biomeEnglish
A large region of the earth with a similar climate, plants and animals, such as a rain forest, desert or tundra.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6)
A large region of the earth with a similar climate, plants and animals, such as a rain forest, desert or tundra.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6)
Black DeathEnglish
The great epidemic of plague, caused by the bacterium Yersinia pestis, that swept Asia, the Middle East and Europe in the 1340s.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
The great epidemic of plague, caused by the bacterium Yersinia pestis, that swept Asia, the Middle East and Europe in the 1340s.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
Black ShipsEnglish
Japanese name (kurofune) for Western ships, especially the dark-hulled, smoke-belching steam warships of Commodore Matthew Perry in 1853.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
Japanese name (kurofune) for Western ships, especially the dark-hulled, smoke-belching steam warships of Commodore Matthew Perry in 1853.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
blast furnaceEnglish
A tall furnace into which iron ore, fuel and limestone are loaded from the top while air is blown in at the bottom, producing molten iron.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
A tall furnace into which iron ore, fuel and limestone are loaded from the top while air is blown in at the bottom, producing molten iron.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
blastpipeEnglish
A pipe that sends used steam up the chimney in strong puffs, drawing air through the fire and making it burn hotter the harder the engine works.
Technology Overcoming Geography, Lesson 2.3 (grade 9–12)
A pipe that sends used steam up the chimney in strong puffs, drawing air through the fire and making it burn hotter the harder the engine works.
Technology Overcoming Geography, Lesson 2.3 (grade 9–12)
blightEnglish
A plant disease that makes leaves and roots wither and rot, like the blight that struck Ireland’s potatoes in 1845.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)
A plant disease that makes leaves and roots wither and rot, like the blight that struck Ireland’s potatoes in 1845.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)
Board of LongitudeEnglish
The group of men named by the Longitude Act of 1714 to judge new methods of finding longitude and to give out the prize money.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.1 (grade 5)
The group of men named by the Longitude Act of 1714 to judge new methods of finding longitude and to give out the prize money.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.1 (grade 5)
boatEnglish
Something people build to float and carry people and things across water.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.4 (grade K)
Something people build to float and carry people and things across water.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.4 (grade K)
bogieEnglish
The wheeled frame under each end of a railway car. At a break of gauge, cars can be lifted and their bogies swapped for bogies of the other gauge.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
The wheeled frame under each end of a railway car. At a break of gauge, cars can be lifted and their bogies swapped for bogies of the other gauge.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
boilerEnglish
The big closed tank where water is heated by fire until it turns into steam.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.3 (grade 4)
The big closed tank where water is heated by fire until it turns into steam.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.3 (grade 4)
bonded warehouseEnglish
A guarded warehouse where imported goods are stored under lock until the duties (import taxes) on them are paid.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
A guarded warehouse where imported goods are stored under lock until the duties (import taxes) on them are paid.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
BosporusEnglish
The strait, about 19 miles (31 km) long and as narrow as about 2,300 feet (700 m), that divides Europe from Asia at Istanbul.
Geography and History: Why Borders Fall Where They Do, Lesson 6.1 (grade 9–12)
The strait, about 19 miles (31 km) long and as narrow as about 2,300 feet (700 m), that divides Europe from Asia at Istanbul.
Geography and History: Why Borders Fall Where They Do, Lesson 6.1 (grade 9–12)
boundary commissionEnglish
A team of surveyors, astronomers and laborers appointed by two governments to mark an agreed boundary on the ground, usually working side by side and checking each other.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
A team of surveyors, astronomers and laborers appointed by two governments to mark an agreed boundary on the ground, usually working side by side and checking each other.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
brain drainEnglish
The emigration of educated and skilled people (doctors, engineers, nurses) from a country, which may weaken the country they leave.
Human Geography, Lesson 3.4 (grade 9–12)
The emigration of educated and skilled people (doctors, engineers, nurses) from a country, which may weaken the country they leave.
Human Geography, Lesson 3.4 (grade 9–12)
branch (of a religion)English
A large, basic division within a religion: Catholic, Orthodox and Protestant in Christianity; Sunni and Shia in Islam; Theravada, Mahayana and Vajrayana in Buddhism.
Human Geography, Lesson 4.3 (grade 9–12)
A large, basic division within a religion: Catholic, Orthodox and Protestant in Christianity; Sunni and Shia in Islam; Theravada, Mahayana and Vajrayana in Buddhism.
Human Geography, Lesson 4.3 (grade 9–12)
breadbasketEnglish
A region that grows far more grain than its people eat and exports the rest, such as the U.S. Corn Belt and Great Plains, the Canadian Prairies, the Argentine Pampas and the black-earth lands of Ukraine and southern Russia.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
A region that grows far more grain than its people eat and exports the rest, such as the U.S. Corn Belt and Great Plains, the Canadian Prairies, the Argentine Pampas and the black-earth lands of Ukraine and southern Russia.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
break of bulkEnglish
A place where cargo must be unloaded from one kind of transport and loaded onto another, such as from ship to wagon.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
A place where cargo must be unloaded from one kind of transport and loaded onto another, such as from ship to wagon.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
break of gaugeEnglish
A place where railways of different gauges meet, so that trains cannot run straight through.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12) · Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
A place where railways of different gauges meet, so that trains cannot run straight through.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12) · Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
break-in-bulk pointEnglish
A place where cargo must be unloaded from one kind of transport and loaded onto another, such as a river landing, port or rail yard.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.2 (grade 8)
A place where cargo must be unloaded from one kind of transport and loaded onto another, such as a river landing, port or rail yard.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.2 (grade 8)
break-of-bulk pointEnglish
A place where cargo must be moved from one kind of transport to another (or from one ship to another), which often makes it a natural site for a trading city.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12) · Human Geography, Lesson 7.1 (grade 9–12) · +1 more
A place where cargo must be moved from one kind of transport to another (or from one ship to another), which often makes it a natural site for a trading city.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12) · Human Geography, Lesson 7.1 (grade 9–12) · +1 more
bridgeheadEnglish
A secure foothold on a coast from which an outside power can land and supply forces; Mackinder named France as the bridgehead of the Midland Ocean powers.
Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12)
A secure foothold on a coast from which an outside power can land and supply forces; Mackinder named France as the bridgehead of the Midland Ocean powers.
Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12)
buffer stateEnglish
A smaller, independent state lying between two larger rival powers, which keeps them from sharing a border and so reduces the risk of war between them.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
A smaller, independent state lying between two larger rival powers, which keeps them from sharing a border and so reduces the risk of war between them.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
buffer tierEnglish
Mackinder’s proposed belt of independent states between Germany and Russia, meant to keep either from controlling East Europe.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
Mackinder’s proposed belt of independent states between Germany and Russia, meant to keep either from controlling East Europe.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
buildingEnglish
A house or other place with walls and a roof that people make, like a store or a library.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 6.1 (grade K)
A house or other place with walls and a roof that people make, like a store or a library.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 6.1 (grade K)
bunkerEnglish
A compartment in a ship where its fuel (coal, later oil) is stored. “Bunkering” means taking on fuel.
Technology Overcoming Geography, Lesson 1.4 (grade 9–12)
A compartment in a ship where its fuel (coal, later oil) is stored. “Bunkering” means taking on fuel.
Technology Overcoming Geography, Lesson 1.4 (grade 9–12)
butteEnglish
A flat-topped hill with steep sides, smaller than a mesa and taller than it is wide.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.2 (grade 4)
A flat-topped hill with steep sides, smaller than a mesa and taller than it is wide.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.2 (grade 4)
bypass pipelineEnglish
A pipeline built to carry oil around a choke point, so that some of it can still reach the sea if the strait is closed.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12)
A pipeline built to carry oil around a choke point, so that some of it can still reach the sea if the strait is closed.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12)
C
cactusEnglish
A desert plant with a thick, waxy skin and spines that stores water inside.
Grade 1 Geography: Maps and Journeys, Lesson 3.3 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.1 (grade 2) · Grade 1 Life Science: Animal Homes and Habits, Lesson 4.3 (grade 1)
A desert plant with a thick, waxy skin and spines that stores water inside.
Grade 1 Geography: Maps and Journeys, Lesson 3.3 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.1 (grade 2) · Grade 1 Life Science: Animal Homes and Habits, Lesson 4.3 (grade 1)
CalicutEnglish
A rich trading city on the Malabar coast of southwest India, at about 11° north, now called Kozhikode. Da Gama arrived there in May 1498.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.3 (grade 5)
A rich trading city on the Malabar coast of southwest India, at about 11° north, now called Kozhikode. Da Gama arrived there in May 1498.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.3 (grade 5)
campsiteEnglish
A place where travelers stop to sleep for the night.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.4 (grade 2)
A place where travelers stop to sleep for the night.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.4 (grade 2)
CanadaEnglish
The big country to the north of the United States. Its capital is Ottawa.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1)
The big country to the north of the United States. Its capital is Ottawa.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1)
Canadian ShieldEnglish
A giant area of very old, hard rock wrapped around Hudson Bay, covered with thin soil, forests and thousands of lakes.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.1 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
A giant area of very old, hard rock wrapped around Hudson Bay, covered with thin soil, forests and thousands of lakes.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.1 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
canoeEnglish
A long, narrow boat that people move with paddles. Some are made by hollowing out a big log.
Grade 1 Geography: Maps and Journeys, Lesson 8.3 (grade 1) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 8.2 (grade K)
A long, narrow boat that people move with paddles. Some are made by hollowing out a big log.
Grade 1 Geography: Maps and Journeys, Lesson 8.3 (grade 1) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 8.2 (grade K)
capeEnglish
A point of land that sticks out into the sea. Sailors use capes as landmarks, and some capes are dangerous to pass.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.1 (grade 5)
A point of land that sticks out into the sea. Sailors use capes as landmarks, and some capes are dangerous to pass.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.1 (grade 5)
Cape AgulhasEnglish
The true southernmost point of Africa, about 90 miles (150 km) east-southeast of the Cape of Good Hope.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5)
The true southernmost point of Africa, about 90 miles (150 km) east-southeast of the Cape of Good Hope.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5)
Cape of Good HopeEnglish
A rocky point of land near the southern tip of Africa. Ships sailing between the Indian Ocean and the Atlantic pass it.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.3 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.1 (grade 5)
A rocky point of land near the southern tip of Africa. Ships sailing between the Indian Ocean and the Atlantic pass it.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.3 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.1 (grade 5)
Cape RouteEnglish
The sea route from Europe around the Cape of Good Hope at the southern tip of Africa to India and the East, first sailed by Vasco da Gama in 1497–1498.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.5 (grade 9–12)
The sea route from Europe around the Cape of Good Hope at the southern tip of Africa to India and the East, first sailed by Vasco da Gama in 1497–1498.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.5 (grade 9–12)
capitolEnglish
The building where lawmakers meet. Spelled with an o, like the round dome on top.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.2 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.1 (grade 4)
The building where lawmakers meet. Spelled with an o, like the round dome on top.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.2 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.1 (grade 4)
carrackEnglish
A large three- or four-masted ship of the 1400s and 1500s that combined square sails for power with a triangular lateen sail at the stern for steering, high castles fore and aft, and a deep hold for long voyages.
Technology Overcoming Geography, Lesson 1.1 (grade 9–12)
A large three- or four-masted ship of the 1400s and 1500s that combined square sails for power with a triangular lateen sail at the stern for steering, high castles fore and aft, and a deep hold for long voyages.
Technology Overcoming Geography, Lesson 1.1 (grade 9–12)
cartoucheEnglish
A decorated frame on a map, often like a scroll or a carved shield, that holds the title, the mapmaker’s name, the date or the scale.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.3 (grade 5)
A decorated frame on a map, often like a scroll or a carved shield, that holds the title, the mapmaker’s name, the date or the scale.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.3 (grade 5)
cash cropEnglish
A crop grown mainly to sell, such as tobacco or cotton, rather than to feed the farmer’s family.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4)
A crop grown mainly to sell, such as tobacco or cotton, rather than to feed the farmer’s family.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4)
cataractEnglish
A stretch of rapids or a large waterfall on a river, such as the six cataracts of the Nile.
Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.1 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12)
A stretch of rapids or a large waterfall on a river, such as the six cataracts of the Nile.
Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.1 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12)
catching featureEnglish
A feature just past the control (a road, a lake shore) that tells you that you have gone too far.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
A feature just past the control (a road, a lake shore) that tells you that you have gone too far.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
cattle driveEnglish
Moving a large herd of cattle on foot over a long trail to a market or a railroad.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4)
Moving a large herd of cattle on foot over a long trail to a market or a railroad.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4)
cenoteEnglish
A natural well or sinkhole in the limestone of the Yucatán Peninsula, where the roof of an underground river or cave has fallen in. The Maya depended on them for water.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
A natural well or sinkhole in the limestone of the Yucatán Peninsula, where the roof of an underground river or cave has fallen in. The Maya depended on them for water.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
census tractEnglish
A small statistical area used by the U.S. Census Bureau, usually with 1,200 to 8,000 people (about 4,000 on average). Tracts are divided into block groups and blocks.
Human Geography, Lesson 1.3 (grade 9–12)
A small statistical area used by the U.S. Census Bureau, usually with 1,200 to 8,000 people (about 4,000 on average). Tracts are divided into block groups and blocks.
Human Geography, Lesson 1.3 (grade 9–12)
center of populationEnglish
The point on which a flat, weightless map of a country would balance if every person weighed the same. The U.S. Census Bureau calculates it after each census.
Human Geography, Lesson 2.1 (grade 9–12)
The point on which a flat, weightless map of a country would balance if every person weighed the same. The U.S. Census Bureau calculates it after each census.
Human Geography, Lesson 2.1 (grade 9–12)
center-pivot irrigationEnglish
A long sprinkler pipe on wheeled towers that rotates around a central well, watering a circular field; patented by Frank Zybach in 1952.
Human Geography, Lesson 6.3 (grade 9–12)
A long sprinkler pipe on wheeled towers that rotates around a central well, watering a circular field; patented by Frank Zybach in 1952.
Human Geography, Lesson 6.3 (grade 9–12)
central business district (CBD)English
The commercial heart of a city, with the highest land values, tallest buildings and greatest concentration of offices and stores.
Human Geography, Lesson 7.3 (grade 9–12)
The commercial heart of a city, with the highest land values, tallest buildings and greatest concentration of offices and stores.
Human Geography, Lesson 7.3 (grade 9–12)
central placeEnglish
A settlement that provides goods and services to the people of the surrounding area (its hinterland or market area).
Human Geography, Lesson 7.2 (grade 9–12)
A settlement that provides goods and services to the people of the surrounding area (its hinterland or market area).
Human Geography, Lesson 7.2 (grade 9–12)
Central ValleyEnglish
The long, fertile valley in central Chile between the Coastal Range and the Andes, where Santiago lies and most Chileans live.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
The long, fertile valley in central Chile between the Coastal Range and the Andes, where Santiago lies and most Chileans live.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
centrifugal forceEnglish
Anything that pulls a state apart, such as deep regional differences of language or religion, great distance, or a sense of unfair treatment.
Human Geography, Lesson 5.3 (grade 9–12)
Anything that pulls a state apart, such as deep regional differences of language or religion, great distance, or a sense of unfair treatment.
Human Geography, Lesson 5.3 (grade 9–12)
Cerro RicoEnglish
“Rich Hill,” the mountain above Potosí in the Bolivian Andes whose silver veins made it the greatest silver source in the world in the late 1500s.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.2 (grade 9–12)
“Rich Hill,” the mountain above Potosí in the Bolivian Andes whose silver veins made it the greatest silver source in the world in the late 1500s.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.2 (grade 9–12)
cessionEnglish
Land given up by one country to another by treaty. The Mexican Cession of 1848 included California and New Mexico.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
Land given up by one country to another by treaty. The Mexican Cession of 1848 included California and New Mexico.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
chalk marlEnglish
A soft layer of chalky clay beneath the Strait of Dover. It is easy to cut and holds back water fairly well, so the Channel Tunnel was bored within it.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
A soft layer of chalky clay beneath the Strait of Dover. It is easy to cut and holds back water fairly well, so the Channel Tunnel was bored within it.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
Challenger DeepEnglish
The deepest known spot in the ocean, at the bottom of the Mariana Trench, about 36,000 feet deep.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.4 (grade 3)
The deepest known spot in the ocean, at the bottom of the Mariana Trench, about 36,000 feet deep.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.4 (grade 3)
character of the governmentEnglish
Whether a nation’s rulers and institutions pursue sea power wisely and steadily over many years.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
Whether a nation’s rulers and institutions pursue sea power wisely and steadily over many years.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
chart datumEnglish
The low-water level from which depths on a nautical chart are measured; the tide adds water above it.
Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
The low-water level from which depths on a nautical chart are measured; the tide adds water above it.
Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
chasquiEnglish
A runner who carried messages along the Inca roads, passing them to the next runner like a relay race.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.3 (grade 3)
A runner who carried messages along the Inca roads, passing them to the next runner like a relay race.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.3 (grade 3)
chemical weatheringEnglish
Breaking down rock by changing its minerals, as when rainwater dissolves limestone or feldspar turns to clay.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.1 (grade 6)
Breaking down rock by changing its minerals, as when rainwater dissolves limestone or feldspar turns to clay.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.1 (grade 6)
chiefEnglish
A ruler or leader of a people. Kalaniʻōpuʻu was the ruling chief of the island of Hawaii when Cook arrived.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
A ruler or leader of a people. Kalaniʻōpuʻu was the ruling chief of the island of Hawaii when Cook arrived.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
chinampaEnglish
A raised garden bed built up from mud and plants in a shallow lake. The Aztecs grew corn, beans and squash on chinampas around Tenochtitlan.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
A raised garden bed built up from mud and plants in a shallow lake. The Aztecs grew corn, beans and squash on chinampas around Tenochtitlan.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
Chinese charactersEnglish
The written signs of Chinese, each standing for a word or part of a word. People who speak very different dialects can read the same characters.
Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7)
The written signs of Chinese, each standing for a word or part of a word. People who speak very different dialects can read the same characters.
Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7)
Chinese Eastern RailwayEnglish
A Russian-built shortcut across Manchuria from near Chita through Harbin to Vladivostok, with a branch south to Port Arthur, built under agreements with China from 1896.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7)
A Russian-built shortcut across Manchuria from near Chita through Harbin to Vladivostok, with a branch south to Port Arthur, built under agreements with China from 1896.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7)
chip logEnglish
A small weighted wooden board tied to a long knotted line. Thrown off the back of a ship, it stays nearly still in the water while the line runs out, showing the ship’s speed.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
A small weighted wooden board tied to a long knotted line. Thrown off the back of a ship, it stays nearly still in the water while the line runs out, showing the ship’s speed.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
choke pointEnglish
A narrow place on a trade route where traffic is crowded together, so that a blockage, accident or attack there would hold up a large share of the world’s trade.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.2 (grade 7) · +3 more
A narrow place on a trade route where traffic is crowded together, so that a blockage, accident or attack there would hold up a large share of the world’s trade.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.2 (grade 7) · +3 more
choropleth mapEnglish
A thematic map that shades whole areas, such as countries or states, lighter or darker according to a number for each area.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Human Geography, Lesson 1.1 (grade 9–12) · Human Geography, Lesson 10.2 (grade 9–12)
A thematic map that shades whole areas, such as countries or states, lighter or darker according to a number for each area.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Human Geography, Lesson 1.1 (grade 9–12) · Human Geography, Lesson 10.2 (grade 9–12)
Church of the EastEnglish
The Christian church of Persia and Mesopotamia, often called “Nestorian,” whose monks and merchants carried the gospel across Central Asia to China by A.D. 635.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
The Christian church of Persia and Mesopotamia, often called “Nestorian,” whose monks and merchants carried the gospel across Central Asia to China by A.D. 635.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
citadelEnglish
A fortress on high ground that protects a city and serves as its last stronghold.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
A fortress on high ground that protects a city and serves as its last stronghold.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
city-stateEnglish
A city that rules itself and the farmland around it, like Ur, Uruk and Lagash in Sumer.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.2 (grade 8)
A city that rules itself and the farmland around it, like Ur, Uruk and Lagash in Sumer.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.2 (grade 8)
classEnglish
A range of numbers (for example, 5 to 20 million people) that all get the same color or shade on a thematic map.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Grade 4 Life Science: Classification, Lesson 2.1 (grade 4) · Statistics, Lesson 1.4 (grade 11–12)
A range of numbers (for example, 5 to 20 million people) that all get the same color or shade on a thematic map.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Grade 4 Life Science: Classification, Lesson 2.1 (grade 4) · Statistics, Lesson 1.4 (grade 11–12)
cliff dwellingEnglish
A home of stone built under the overhang of a cliff, like a house in a giant shelf of rock.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2)
A home of stone built under the overhang of a cliff, like a house in a giant shelf of rock.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2)
climate chartEnglish
A graph of a place’s average weather month by month, usually with temperature as a line and precipitation as bars.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
A graph of a place’s average weather month by month, usually with temperature as a line and precipitation as bars.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
climate classificationEnglish
A system for sorting the world’s climates into types by clear rules, so that places with similar climates get the same name.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
A system for sorting the world’s climates into types by clear rules, so that places with similar climates get the same name.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
climographEnglish
A graph of a place’s climate showing average precipitation for each month as bars and average temperature for each month as a line.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.1 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
A graph of a place’s climate showing average precipitation for each month as bars and average temperature for each month as a line.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.1 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
closed political systemEnglish
Mackinder’s phrase for a world with no empty spaces left to claim, in which every gain by one power is felt by the others.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
Mackinder’s phrase for a world with no empty spaces left to claim, in which every gain by one power is felt by the others.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
closed seaEnglish
A sea whose only exits are narrow straits held or watched by other powers, such as the Baltic or the Black Sea.
Geopolitics: The Great Ideas, Lesson 5.3 (grade 9–12)
A sea whose only exits are narrow straits held or watched by other powers, such as the Baltic or the Black Sea.
Geopolitics: The Great Ideas, Lesson 5.3 (grade 9–12)
closure errorEnglish
How far a traverse misses its starting point when the measured sides are plotted. A small closure error shows careful work.
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
How far a traverse misses its starting point when the measured sides are plotted. A small closure error shows careful work.
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
coalfieldEnglish
A region where coal seams lie close enough to the surface to be mined, such as South Wales, Yorkshire or the Ruhr.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12) · Human Geography, Lesson 8.1 (grade 9–12)
A region where coal seams lie close enough to the surface to be mined, such as South Wales, Yorkshire or the Ruhr.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12) · Human Geography, Lesson 8.1 (grade 9–12)
coaling stationEnglish
A harbor with stocks of coal, docks and workshops where steamships could refuel and repair; essential to any navy that sailed far from home before oil and refueling at sea.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12) · Technology Overcoming Geography, Lesson 1.4 (grade 9–12)
A harbor with stocks of coal, docks and workshops where steamships could refuel and repair; essential to any navy that sailed far from home before oil and refueling at sea.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12) · Technology Overcoming Geography, Lesson 1.4 (grade 9–12)
coast to coastEnglish
All the way across our country, from the Atlantic Ocean on the east to the Pacific Ocean on the west.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.4 (grade 2)
All the way across our country, from the Atlantic Ocean on the east to the Pacific Ocean on the west.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.4 (grade 2)
coastal desertEnglish
A desert along an ocean shore, kept dry by cold currents and sinking air. The Atacama is one of the driest places on earth.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
A desert along an ocean shore, kept dry by cold currents and sinking air. The Atacama is one of the driest places on earth.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
coastal plainEnglish
The low, flat land of sand and clay between the fall line and the ocean.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4)
The low, flat land of sand and clay between the fall line and the ocean.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4)
cognateEnglish
A word in one language that comes from the same ancestral word as a word in another language (Latin pater and English father).
Human Geography, Lesson 4.1 (grade 9–12) · Grade 5 Spanish, Lesson 1.2 (grade 5)
A word in one language that comes from the same ancestral word as a word in another language (Latin pater and English father).
Human Geography, Lesson 4.1 (grade 9–12) · Grade 5 Spanish, Lesson 1.2 (grade 5)
cohortEnglish
A group of people born in the same period, such as the five-year band born 1946–1950, who move up the pyramid together as they age.
Human Geography, Lesson 2.4 (grade 9–12)
A group of people born in the same period, such as the five-year band born 1946–1950, who move up the pyramid together as they age.
Human Geography, Lesson 2.4 (grade 9–12)
cokeEnglish
Coal baked in a closed oven to drive off tar and gases, leaving nearly pure carbon that burns hot and is strong enough to hold up a tall furnace load.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12) · Human Geography, Lesson 8.1 (grade 9–12)
Coal baked in a closed oven to drive off tar and gases, leaving nearly pure carbon that burns hot and is strong enough to hold up a tall furnace load.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12) · Human Geography, Lesson 8.1 (grade 9–12)
colEnglish
A low pass or saddle on a ridge between two peaks. The South Col lies between Everest and its neighbor Lhotse.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.4 (grade 5)
A low pass or saddle on a ridge between two peaks. The South Col lies between Everest and its neighbor Lhotse.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.4 (grade 5)
collective securityEnglish
An arrangement in which states agree to defend one another, so that an aggressor faces the combined strength of all.
Human Geography, Lesson 5.4 (grade 9–12)
An arrangement in which states agree to defend one another, so that an aggressor faces the combined strength of all.
Human Geography, Lesson 5.4 (grade 9–12)
colliding (convergent) boundaryEnglish
A plate edge where two plates push together. One plate may slide down under the other, or the crust may crumple into mountains.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.2 (grade 6)
A plate edge where two plates push together. One plate may slide down under the other, or the crust may crumple into mountains.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.2 (grade 6)
collierEnglish
A cargo ship that carried coal to fuel warships at sea or in distant harbors.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
A cargo ship that carried coal to fuel warships at sea or in distant harbors.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
Columbian epochEnglish
Mackinder’s name for the roughly four centuries after Columbus, when European sea powers explored and claimed most of the world against little resistance.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
Mackinder’s name for the roughly four centuries after Columbus, when European sea powers explored and claimed most of the world against little resistance.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
command of the seaEnglish
Control of the important sea routes in war, so that your own ships can pass and the enemy’s cannot. Mahan held that it is won chiefly by defeating or bottling up the enemy’s battle fleet.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 5.1 (grade 9–12)
Control of the important sea routes in war, so that your own ships can pass and the enemy’s cannot. Mahan held that it is won chiefly by defeating or bottling up the enemy’s battle fleet.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 5.1 (grade 9–12)
commerce raiding (guerre de course)English
War against an enemy’s merchant ships by cruisers or privateers. Mahan judged that it could hurt an enemy but could not by itself win a war against a nation that held command of the sea.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12)
War against an enemy’s merchant ships by cruisers or privateers. Mahan judged that it could hurt an enemy but could not by itself win a war against a nation that held command of the sea.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12)
commercial agricultureEnglish
Farming mainly to sell crops and animals off the farm, usually on a larger scale with machines.
Human Geography, Lesson 6.4 (grade 9–12)
Farming mainly to sell crops and animals off the farm, usually on a larger scale with machines.
Human Geography, Lesson 6.4 (grade 9–12)
compass deviationEnglish
The error in a ship’s compass caused by the ship’s own iron. It must be measured and corrected with magnets or iron balls placed near the compass.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
The error in a ship’s compass caused by the ship’s own iron. It must be measured and corrected with magnets or iron balls placed near the compass.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
competing hypothesesEnglish
Two or more explanations of the same facts, weighed side by side. A strong conclusion says what follows under each one.
Geopolitics: The Great Ideas, Lesson 5.4 (grade 9–12)
Two or more explanations of the same facts, weighed side by side. A strong conclusion says what follows under each one.
Geopolitics: The Great Ideas, Lesson 5.4 (grade 9–12)
complementarityEnglish
When one region has what another lacks and lacks what the other has, so that both gain by trading.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
When one region has what another lacks and lacks what the other has, so that both gain by trading.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
composite bowEnglish
A short, powerful bow made of wood, horn and sinew glued in layers, small enough to shoot from horseback.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
A short, powerful bow made of wood, horn and sinew glued in layers, small enough to shoot from horseback.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
composite hullEnglish
A hull with an iron frame and wooden planking. The wood could be sheathed in copper alloy to keep off weed and shipworm, which could not be done on iron without corrosion.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
A hull with an iron frame and wooden planking. The wood could be sheathed in copper alloy to keep off weed and shipworm, which could not be done on iron without corrosion.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
composite scoreEnglish
The combined weighted score of both exam sections, which the testing organization converts to a final score; the cutoffs vary from year to year and are set after each exam.
Human Geography, Lesson 10.4 (grade 9–12)
The combined weighted score of both exam sections, which the testing organization converts to a final score; the cutoffs vary from year to year and are set after each exam.
Human Geography, Lesson 10.4 (grade 9–12)
composite volcanoEnglish
A tall, steep volcano built of alternating layers of lava and ash; also called a stratovolcano.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 3.2 (grade 6)
A tall, steep volcano built of alternating layers of lava and ash; also called a stratovolcano.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 3.2 (grade 6)
compression and tensionEnglish
Compression is a pushing force that squeezes a member; tension is a pulling force that stretches it. In the Forth Bridge, great steel tubes carry compression and lattice girders carry tension.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
Compression is a pushing force that squeezes a member; tension is a pulling force that stretches it. In the Forth Bridge, great steel tubes carry compression and lattice girders carry tension.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
compromise mapEnglish
A map that lets sizes and shapes each be a little wrong so that nothing is badly wrong, such as the Robinson or Winkel tripel map.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.4 (grade 5)
A map that lets sizes and shapes each be a little wrong so that nothing is badly wrong, such as the Robinson or Winkel tripel map.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.4 (grade 5)
concentrationEnglish
Keeping the battle fleet together so that it can beat the enemy’s fleet, instead of dividing it to guard many places at once. One of Mahan’s chief principles.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12)
Keeping the battle fleet together so that it can beat the enemy’s fleet, instead of dividing it to guard many places at once. One of Mahan’s chief principles.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12)
concentric zone modelEnglish
Ernest Burgess’s model (1925) of a city as five zones: the CBD at the center and four rings around it (zone in transition, workingmen’s homes, residential zone and commuters’ zone).
Human Geography, Lesson 7.3 (grade 9–12)
Ernest Burgess’s model (1925) of a city as five zones: the CBD at the center and four rings around it (zone in transition, workingmen’s homes, residential zone and commuters’ zone).
Human Geography, Lesson 7.3 (grade 9–12)
confederationEnglish
A loose union of sovereign states that keep most power for themselves and give the central body only limited tasks, as under the American Articles of Confederation (1781–1789).
Human Geography, Lesson 5.3 (grade 9–12)
A loose union of sovereign states that keep most power for themselves and give the central body only limited tasks, as under the American Articles of Confederation (1781–1789).
Human Geography, Lesson 5.3 (grade 9–12)
confluenceEnglish
A place where two rivers meet and flow on together as one river.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.2 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.2 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 5.2 (grade 7) · +3 more
A place where two rivers meet and flow on together as one river.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.2 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.2 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 5.2 (grade 7) · +3 more
conformal and equal-area projectionsEnglish
A conformal projection keeps the shapes of small areas and true angles (Mercator); an equal-area projection keeps the relative sizes of areas but bends shapes (Gall–Peters, Goode’s homolosine). No projection can be both.
Human Geography, Lesson 1.1 (grade 9–12)
A conformal projection keeps the shapes of small areas and true angles (Mercator); an equal-area projection keeps the relative sizes of areas but bends shapes (Gall–Peters, Goode’s homolosine). No projection can be both.
Human Geography, Lesson 1.1 (grade 9–12)
coniferEnglish
A cone-bearing tree, usually with needles, such as spruce, fir, pine or larch. Most are evergreen.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6) · Grade 4 Life Science: Classification, Lesson 6.2 (grade 4)
A cone-bearing tree, usually with needles, such as spruce, fir, pine or larch. Most are evergreen.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6) · Grade 4 Life Science: Classification, Lesson 6.2 (grade 4)
conquestEnglish
Taking control of a land and its people by force.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.2 (grade 5)
Taking control of a land and its people by force.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.2 (grade 5)
conservation (wise use)English
The view, associated with Gifford Pinchot, that natural resources should be used and managed efficiently for the long-term good of the people.
Human Geography, Lesson 9.3 (grade 9–12)
The view, associated with Gifford Pinchot, that natural resources should be used and managed efficiently for the long-term good of the people.
Human Geography, Lesson 9.3 (grade 9–12)
contagious diffusionEnglish
Spread from person to person and place to neighboring place, outward through a population like ripples.
Human Geography, Lesson 4.2 (grade 9–12)
Spread from person to person and place to neighboring place, outward through a population like ripples.
Human Geography, Lesson 4.2 (grade 9–12)
containmentEnglish
The American policy, named by Kennan in 1947, of holding Soviet expansion in check by firm counterpressure wherever it pushed, while waiting for Soviet power to change or weaken from within.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
The American policy, named by Kennan in 1947, of holding Soviet expansion in check by firm counterpressure wherever it pushed, while waiting for Soviet power to change or weaken from within.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
content clueEnglish
Something a map shows that can be dated: a place name, a border, a state, a canal, a railroad.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
Something a map shows that can be dated: a place name, a border, a state, a canal, a railroad.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
contiguousEnglish
Touching; sharing a border. The boundary commissions were told to divide the provinces by “contiguous majority areas,” so that each country’s land would be joined together, not scattered in islands.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
Touching; sharing a border. The boundary commissions were told to divide the provinces by “contiguous majority areas,” so that each country’s land would be joined together, not scattered in islands.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
contiguous empireEnglish
An empire whose lands touch one another in a single unbroken block, as opposed to one spread across oceans.
Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
An empire whose lands touch one another in a single unbroken block, as opposed to one spread across oceans.
Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
continental climateEnglish
A climate far from the moderating sea, with hot summers and cold winters (Köppen’s group D).
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
A climate far from the moderating sea, with hot summers and cold winters (Köppen’s group D).
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
continentalityEnglish
The effect of being far from the ocean: drier air, hot summers and very cold winters.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.2 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
The effect of being far from the ocean: drier air, hot summers and very cold winters.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.2 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
contour VEnglish
The bend a contour line makes where it crosses a stream. The point of the V always aims upstream, toward higher ground.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.1 (grade 6)
The bend a contour line makes where it crosses a stream. The point of the V always aims upstream, toward higher ground.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.1 (grade 6)
convection currentEnglish
A flow in a liquid or gas set up when warm, lighter fluid rises and cool, heavier fluid sinks.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
A flow in a liquid or gas set up when warm, lighter fluid rises and cool, heavier fluid sinks.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
copperplate engravingEnglish
A printing method in which lines are cut into a copper plate, inked and pressed onto paper; common for maps from the 1500s to the 1800s.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
A printing method in which lines are cut into a copper plate, inked and pressed onto paper; common for maps from the 1500s to the 1800s.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
co-principalityEnglish
A state with two princes. Andorra’s co-princes are the Bishop of Urgell in Spain and the President of France.
Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
A state with two princes. Andorra’s co-princes are the Bishop of Urgell in Spain and the President of France.
Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
coral reefEnglish
A long ridge in warm, shallow sea built from the stony skeletons of millions of tiny animals called coral polyps.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.3 (grade 3) · Grade 3 Life Science: Plants and Animals Together, Lesson 5.3 (grade 3)
A long ridge in warm, shallow sea built from the stony skeletons of millions of tiny animals called coral polyps.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.3 (grade 3) · Grade 3 Life Science: Plants and Animals Together, Lesson 5.3 (grade 3)
cordilleraEnglish
Spanish for a mountain chain. The Andes are often called simply “the Cordillera” in Chile and Argentina.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
Spanish for a mountain chain. The Andes are often called simply “the Cordillera” in Chile and Argentina.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
core areaEnglish
The region where a state began and where its population, wealth, capital and power are concentrated, usually a fertile, well-watered lowland with easy communications.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12)
The region where a state began and where its population, wealth, capital and power are concentrated, usually a fertile, well-watered lowland with easy communications.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12)
Coriolis effectEnglish
Because the earth turns, anything moving freely over its surface (wind, water, a long-range shell) is turned to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.2 (grade 6)
Because the earth turns, anything moving freely over its surface (wind, water, a long-range shell) is turned to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.2 (grade 6)
Corn BeltEnglish
The farming region of the Midwest, centered on Iowa, Illinois, Indiana and nearby states, where corn is the main crop.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.2 (grade 4)
The farming region of the Midwest, centered on Iowa, Illinois, Indiana and nearby states, where corn is the main crop.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.2 (grade 4)
corridorEnglish
An open path for movement, such as a plain, river valley, mountain pass or strait.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
An open path for movement, such as a plain, river valley, mountain pass or strait.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
corvéeEnglish
Forced, unpaid or poorly paid labor that a government demands of its people. Egyptian peasants were drafted by corvée to dig the Suez Canal in its early years.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.2 (grade 8) · Technology Overcoming Geography, Lesson 3.1 (grade 9–12)
Forced, unpaid or poorly paid labor that a government demands of its people. Egyptian peasants were drafted by corvée to dig the Suez Canal in its early years.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.2 (grade 8) · Technology Overcoming Geography, Lesson 3.1 (grade 9–12)
corvusEnglish
“Raven”: a hinged boarding bridge with an iron spike that Roman ships dropped onto enemy decks so soldiers could fight as if on land.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
“Raven”: a hinged boarding bridge with an iron spike that Roman ships dropped onto enemy decks so soldiers could fight as if on land.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
cosmographyEnglish
An old word for the description of the whole world and the heavens. Waldseemüller’s map was called a Universalis Cosmographia, a description of the whole world.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.2 (grade 5)
An old word for the description of the whole world and the heavens. Waldseemüller’s map was called a Universalis Cosmographia, a description of the whole world.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.2 (grade 5)
counterexampleEnglish
A real case that fits the conditions of a claim but not its conclusion; one solid counterexample defeats a claim that something is always true.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 1.5 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12) · +3 more
A real case that fits the conditions of a claim but not its conclusion; one solid counterexample defeats a claim that something is always true.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 1.5 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12) · +3 more
counterurbanizationEnglish
Movement of people out of large cities to small towns and rural areas.
Human Geography, Lesson 3.3 (grade 9–12)
Movement of people out of large cities to small towns and rural areas.
Human Geography, Lesson 3.3 (grade 9–12)
countryEnglish
A big land with its own name, its own flag and its own leaders. Our country is the United States of America.
Grade 1 Geography: Maps and Journeys, Lesson 6.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.1 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.2 (grade 3) · +1 more
A big land with its own name, its own flag and its own leaders. Our country is the United States of America.
Grade 1 Geography: Maps and Journeys, Lesson 6.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.1 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.2 (grade 3) · +1 more
country (sovereign state)English
A territory with its own government that is independent of any other government and is recognized by other countries.
Grade 7 Geography: Regions of the World, Lesson 9.2 (grade 7)
A territory with its own government that is independent of any other government and is recognized by other countries.
Grade 7 Geography: Regions of the World, Lesson 9.2 (grade 7)
covered drainEnglish
A brick channel running along a street, roofed with bricks or stone slabs, that carried waste water away from the houses.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
A brick channel running along a street, roofed with bricks or stone slabs, that carried waste water away from the houses.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
covered wagonEnglish
A big wooden wagon with a cloth top stretched over hoops, pulled by oxen, mules or horses.
Grade 1 Geography: Maps and Journeys, Lesson 8.4 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.2 (grade 2)
A big wooden wagon with a cloth top stretched over hoops, pulled by oxen, mules or horses.
Grade 1 Geography: Maps and Journeys, Lesson 8.4 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.2 (grade 2)
crag and tailEnglish
A landform shaped by an ice sheet: a steep knob of hard rock (the crag) with a long, gentle ridge of softer rock or debris trailing behind it (the tail), sheltered from the ice.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8)
A landform shaped by an ice sheet: a steep knob of hard rock (the crag) with a long, gentle ridge of softer rock or debris trailing behind it (the tail), sheltered from the ice.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8)
crevasseEnglish
On the Mississippi, a break in a levee through which the river pours out onto the land.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.2 (grade 6)
On the Mississippi, a break in a levee through which the river pours out onto the land.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.2 (grade 6)
crewEnglish
The people who work together on a ship.
Grade 1 Geography: Maps and Journeys, Lesson 8.2 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.3 (grade 3)
The people who work together on a ship.
Grade 1 Geography: Maps and Journeys, Lesson 8.2 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.3 (grade 3)
crossingEnglish
The point where a line of latitude and a line of longitude meet on a map or globe.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.1 (grade 3)
The point where a line of latitude and a line of longitude meet on a map or globe.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.1 (grade 3)
crossroads islandEnglish
An island lying on or between major sea routes, so that whoever holds it can watch, protect or cut the traffic passing by.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
An island lying on or between major sea routes, so that whoever holds it can watch, protect or cut the traffic passing by.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
crown (camber)English
A gentle arch across the width of a road, higher in the middle than at the edges, so that rain runs off into side ditches instead of soaking the roadbed.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
A gentle arch across the width of a road, higher in the middle than at the edges, so that rain runs off into side ditches instead of soaking the roadbed.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
crownstoneEnglish
A larger boundary stone set every fifth mile along the Mason–Dixon Line, carved with the Penn coat of arms on the Pennsylvania side and the Calvert arms on the Maryland side.
Geography and History: Why Borders Fall Where They Do, Lesson 10.1 (grade 9–12)
A larger boundary stone set every fifth mile along the Mason–Dixon Line, carved with the Penn coat of arms on the Pennsylvania side and the Calvert arms on the Maryland side.
Geography and History: Why Borders Fall Where They Do, Lesson 10.1 (grade 9–12)
crude birth rate (CBR)English
The number of live births in a year for every 1,000 people in the population.
Human Geography, Lesson 2.2 (grade 9–12)
The number of live births in a year for every 1,000 people in the population.
Human Geography, Lesson 2.2 (grade 9–12)
crude death rate (CDR)English
The number of deaths in a year for every 1,000 people in the population.
Human Geography, Lesson 2.2 (grade 9–12)
The number of deaths in a year for every 1,000 people in the population.
Human Geography, Lesson 2.2 (grade 9–12)
cursus publicusEnglish
The state courier and transport service founded by Augustus. It carried official messages, officials and government goods, using animals and vehicles kept at stations along the main roads.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12) · Grade 6 Latin, Lesson 2.2 (grade 6)
The state courier and transport service founded by Augustus. It carried official messages, officials and government goods, using animals and vehicles kept at stations along the main roads.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12) · Grade 6 Latin, Lesson 2.2 (grade 6)
curvature correctionEnglish
The amount a distant object’s base drops below a level line because the earth is round, about 0.667 × d² feet for a distance of d miles.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12)
The amount a distant object’s base drops below a level line because the earth is round, about 0.667 × d² feet for a distance of d miles.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12)
Curzon LineEnglish
A line proposed by the British foreign secretary Lord Curzon in 1920, running roughly along the Bug River; the basis of Poland’s eastern border after 1945.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
A line proposed by the British foreign secretary Lord Curzon in 1920, running roughly along the Bug River; the basis of Poland’s eastern border after 1945.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
cut bankEnglish
The steep outer bank of a river bend, where the fastest water wears the bank away.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.4 (grade 6)
The steep outer bank of a river bend, where the fastest water wears the bank away.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.4 (grade 6)
cut bank and point barEnglish
The steep bank on the outside of a bend, where fast water erodes, and the sloping sand bank on the inside, where slow water deposits.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6)
The steep bank on the outside of a bend, where fast water erodes, and the sloping sand bank on the inside, where slow water deposits.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6)
D
damperEnglish
A device that soaks up the energy of a building’s swaying, like a shock absorber on a car.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 3.4 (grade 6)
A device that soaks up the energy of a building’s swaying, like a shock absorber on a car.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 3.4 (grade 6)
Danish StraitsEnglish
The three channels between Denmark, Sweden and Germany that join the Baltic Sea to the Kattegat and the North Sea: the Øresund (the Sound), the Great Belt and the Little Belt.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
The three channels between Denmark, Sweden and Germany that join the Baltic Sea to the Kattegat and the North Sea: the Øresund (the Sound), the Great Belt and the Little Belt.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
DardanellesEnglish
The strait, about 38 miles (61 km) long, joining the Sea of Marmara to the Aegean Sea between the Gallipoli peninsula in Europe and Anatolia in Asia; called the Hellespont in ancient times.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
The strait, about 38 miles (61 km) long, joining the Sea of Marmara to the Aegean Sea between the Gallipoli peninsula in Europe and Anatolia in Asia; called the Hellespont in ancient times.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
Darial GorgeEnglish
The deep gorge of the Terek River through the center of the Greater Caucasus, the main inland gateway; its name comes from Persian words meaning “Gate of the Alans.”
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
The deep gorge of the Terek River through the center of the Greater Caucasus, the main inland gateway; its name comes from Persian words meaning “Gate of the Alans.”
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
Darién GapEnglish
The stretch of swamp, river and rainforest on the border of Panama and Colombia, about 100 km (60 miles) wide, where the Pan-American Highway has never been built.
Technology Overcoming Geography, Lesson 5.4 (grade 9–12)
The stretch of swamp, river and rainforest on the border of Panama and Colombia, about 100 km (60 miles) wide, where the Pan-American Highway has never been built.
Technology Overcoming Geography, Lesson 5.4 (grade 9–12)
day’s runEnglish
The distance a ship covers from one noon to the next, the standard measure of a ship’s progress.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
The distance a ship covers from one noon to the next, the standard measure of a ship’s progress.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
deciduousEnglish
Shedding leaves for part of the year.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6)
Shedding leaves for part of the year.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6)
decimal degreesEnglish
A way to write latitude and longitude as one number, such as 40.6892° N.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
A way to write latitude and longitude as one number, such as 40.6892° N.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
declination tableEnglish
A table telling how far north or south of the equator the sun is on each day of the year. Pilots used it to find latitude from the sun on any day.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.2 (grade 5)
A table telling how far north or south of the equator the sun is on each day of the year. Pilots used it to find latitude from the sun on any day.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.2 (grade 5)
deflection of the verticalEnglish
The small sideways pull of nearby mountains or dense rock on a plumb line, which makes an astronomical latitude differ slightly from the true geometric latitude.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
The small sideways pull of nearby mountains or dense rock on a plumb line, which makes an astronomical latitude differ slightly from the true geometric latitude.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
degree (°)English
A unit for measuring parts of a circle. The little circle ° stands for degrees.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 1.2 (grade 3)
A unit for measuring parts of a circle. The little circle ° stands for degrees.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 1.2 (grade 3)
DejimaEnglish
A small fan-shaped artificial island in Nagasaki harbor where the Dutch were allowed to trade, under close watch, from 1641.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
A small fan-shaped artificial island in Nagasaki harbor where the Dutch were allowed to trade, under close watch, from 1641.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
Delian LeagueEnglish
An alliance of Greek cities, founded in 478 B.C. under Athenian leadership against Persia, that Athens gradually turned into an empire.
Geography and History: Why Borders Fall Where They Do, Lesson 5.4 (grade 9–12)
An alliance of Greek cities, founded in 478 B.C. under Athenian leadership against Persia, that Athens gradually turned into an empire.
Geography and History: Why Borders Fall Where They Do, Lesson 5.4 (grade 9–12)
delimitation and demarcationEnglish
Delimitation is describing a border in words or on a map, usually in a treaty. Demarcation is marking it on the ground with posts, stones, cleared lines or buoys.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
Delimitation is describing a border in words or on a map, usually in a treaty. Demarcation is marking it on the ground with posts, stones, cleared lines or buoys.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
delta lobeEnglish
One part of a delta built while the river flowed in one course; when the river switches course, it begins a new lobe.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.3 (grade 6)
One part of a delta built while the river flowed in one course; when the river switches course, it begins a new lobe.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.3 (grade 6)
Delta WorksEnglish
The great set of dams, sluices and storm surge barriers the Netherlands built after 1953 across the river mouths of the southwest.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.1 (grade 6)
The great set of dams, sluices and storm surge barriers the Netherlands built after 1953 across the river mouths of the southwest.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.1 (grade 6)
demarcationEnglish
Marking a border on the ground (or in the water) with posts, buoys and surveyed points, after a treaty has described it in words.
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
Marking a border on the ground (or in the water) with posts, buoys and surveyed points, after a treaty has described it in words.
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
Demilitarized Zone (DMZ)English
A strip about 2.5 miles (4 km) wide, 2 km on each side of the MDL, running about 155 miles (250 km) across Korea, from which the armistice barred military forces.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
A strip about 2.5 miles (4 km) wide, 2 km on each side of the MDL, running about 155 miles (250 km) across Korea, from which the armistice barred military forces.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
demographic transition modelEnglish
A model describing how a country’s birth and death rates change from high to low over time, producing a burst of growth in between.
Human Geography, Lesson 2.2 (grade 9–12)
A model describing how a country’s birth and death rates change from high to low over time, producing a burst of growth in between.
Human Geography, Lesson 2.2 (grade 9–12)
denominationEnglish
An organized body within a branch, such as the Baptists, Lutherans, Presbyterians or Methodists within Protestant Christianity.
Human Geography, Lesson 4.3 (grade 9–12)
An organized body within a branch, such as the Baptists, Lutherans, Presbyterians or Methodists within Protestant Christianity.
Human Geography, Lesson 4.3 (grade 9–12)
density gradientEnglish
The rate at which population density falls with distance from the city center; Colin Clark (1951) described it as D = D0e−bx.
Human Geography, Lesson 7.3 (grade 9–12)
The rate at which population density falls with distance from the city center; Colin Clark (1951) described it as D = D0e−bx.
Human Geography, Lesson 7.3 (grade 9–12)
dependency ratioEnglish
The number of people of dependent age (under 15 and 65 and over) for every 100 people of working age (15 to 64).
Human Geography, Lesson 10.2 (grade 9–12) · Human Geography, Lesson 2.4 (grade 9–12)
The number of people of dependent age (under 15 and 65 and over) for every 100 people of working age (15 to 64).
Human Geography, Lesson 10.2 (grade 9–12) · Human Geography, Lesson 2.4 (grade 9–12)
dependency theoryEnglish
The view, associated with Raúl Prebisch and Andre Gunder Frank, that poor countries stay poor because their trade ties to rich countries keep them exporting raw materials on unfavorable terms.
Human Geography, Lesson 8.3 (grade 9–12)
The view, associated with Raúl Prebisch and Andre Gunder Frank, that poor countries stay poor because their trade ties to rich countries keep them exporting raw materials on unfavorable terms.
Human Geography, Lesson 8.3 (grade 9–12)
depotEnglish
A store of food and fuel left along a route ahead of time, to be picked up on the way.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5) · Grade 7 Physical Education & Health, Lesson 3.1 (grade 7)
A store of food and fuel left along a route ahead of time, to be picked up on the way.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5) · Grade 7 Physical Education & Health, Lesson 3.1 (grade 7)
depression contourEnglish
A closed contour line with short ticks (hachures) pointing inward, marking a hollow that is lower than the land around it.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.1 (grade 6)
A closed contour line with short ticks (hachures) pointing inward, marking a hollow that is lower than the land around it.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.1 (grade 6)
DerbentEnglish
An ancient fortress city on the narrow strip of land between the Caucasus and the Caspian Sea, the eastern gateway around the range.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
An ancient fortress city on the narrow strip of land between the Caucasus and the Caspian Sea, the eastern gateway around the range.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
determinismEnglish
The claim that geography decides history by itself. The course treats geography as setting costs and opportunities, while people still choose.
Geopolitics: The Great Ideas, Lesson 5.4 (grade 9–12)
The claim that geography decides history by itself. The course treats geography as setting costs and opportunities, while people still choose.
Geopolitics: The Great Ideas, Lesson 5.4 (grade 9–12)
devolutionEnglish
The transfer of some powers from a national government to regional governments, as when the United Kingdom created a Scottish Parliament in 1999.
Human Geography, Lesson 5.3 (grade 9–12)
The transfer of some powers from a national government to regional governments, as when the United Kingdom created a Scottish Parliament in 1999.
Human Geography, Lesson 5.3 (grade 9–12)
DEW LineEnglish
The Distant Early Warning Line, a chain of radar stations across arctic North America, in operation from 1957, built to warn of bombers coming over the Pole.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
The Distant Early Warning Line, a chain of radar stations across arctic North America, in operation from 1957, built to warn of bombers coming over the Pole.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
dhowEnglish
A general name for the traditional sailing ships of the western Indian Ocean, usually with one or two masts and lateen sails. Older dhows had hull planks sewn together with coconut-fiber cord.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12)
A general name for the traditional sailing ships of the western Indian Ocean, usually with one or two masts and lateen sails. Older dhows had hull planks sewn together with coconut-fiber cord.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12)
dialectEnglish
A local form of a language. China’s spoken forms, such as Mandarin, Cantonese and the Wu speech of Shanghai and Ningbo, differ so much that speakers often cannot understand one another.
Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7) · Human Geography, Lesson 4.1 (grade 9–12)
A local form of a language. China’s spoken forms, such as Mandarin, Cantonese and the Wu speech of Shanghai and Ningbo, differ so much that speakers often cannot understand one another.
Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7) · Human Geography, Lesson 4.1 (grade 9–12)
dictumEnglish
A short, formal saying that sums up an argument.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
A short, formal saying that sums up an argument.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
dike (levee)English
A long bank of earth or stone built along a river to keep its water in its channel during floods.
Grade 7 Geography: Regions of the World, Lesson 6.1 (grade 7)
A long bank of earth or stone built along a river to keep its water in its channel during floods.
Grade 7 Geography: Regions of the World, Lesson 6.1 (grade 7)
DiolkosEnglish
A paved trackway across the Isthmus of Corinth, used from about the 6th century B.C., over which ships and cargo were hauled between the two gulfs.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
A paved trackway across the Isthmus of Corinth, used from about the 6th century B.C., over which ships and cargo were hauled between the two gulfs.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
directionsEnglish
Words that tell someone how to get from one place to another.
Grade 1 Geography: Maps and Journeys, Lesson 2.4 (grade 1) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.3 (grade K)
Words that tell someone how to get from one place to another.
Grade 1 Geography: Maps and Journeys, Lesson 2.4 (grade 1) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.3 (grade K)
disasterEnglish
A hazard that actually strikes people and causes great loss of life or property beyond what a community can handle on its own.
Human Geography, Lesson 9.4 (grade 9–12)
A hazard that actually strikes people and causes great loss of life or property beyond what a community can handle on its own.
Human Geography, Lesson 9.4 (grade 9–12)
distance decayEnglish
The tendency for contact and interaction between two places to decline as the distance between them increases.
Human Geography, Lesson 1.2 (grade 9–12) · Human Geography, Lesson 4.4 (grade 9–12)
The tendency for contact and interaction between two places to decline as the distance between them increases.
Human Geography, Lesson 1.2 (grade 9–12) · Human Geography, Lesson 4.4 (grade 9–12)
distress callEnglish
An urgent radio message from a ship in danger, giving its position so others can come to help.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.1 (grade 5)
An urgent radio message from a ship in danger, giving its position so others can come to help.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.1 (grade 5)
distribution centerEnglish
A large warehouse where goods arriving in bulk are sorted and sent out to stores or directly to customers.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
A large warehouse where goods arriving in bulk are sorted and sent out to stores or directly to customers.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
dividersEnglish
A tool with two sharp metal points used to measure distances on a chart against the scale.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.4 (grade 3)
A tool with two sharp metal points used to measure distances on a chart against the scale.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.4 (grade 3)
dogeEnglish
The elected chief magistrate of the Republic of Venice, chosen for life by the city’s leading families through a careful voting process.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.1 (grade 8)
The elected chief magistrate of the Republic of Venice, chosen for life by the city’s leading families through a careful voting process.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.1 (grade 8)
domesticationEnglish
The change of a wild plant or animal, through human selection over many generations, into a form that lives with people and depends on them (for example, wheat whose ripe ears no longer shatter).
Human Geography, Lesson 6.1 (grade 9–12)
The change of a wild plant or animal, through human selection over many generations, into a form that lives with people and depends on them (for example, wheat whose ripe ears no longer shatter).
Human Geography, Lesson 6.1 (grade 9–12)
dot mapEnglish
A thematic map that places one dot for a set number of people or things, so crowded places look crowded and empty places look empty.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7)
A thematic map that places one dot for a set number of people or things, so crowded places look crowded and empty places look empty.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7)
downstreamEnglish
Going with the river’s flow, toward its mouth.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.3 (grade 2)
Going with the river’s flow, toward its mouth.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.3 (grade 2)
drainage basinEnglish
All the land that drains into one river and its tributaries; also called a watershed. Rain falling anywhere in the basin eventually flows past the river’s mouth.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12) · +1 more
All the land that drains into one river and its tributaries; also called a watershed. Rain falling anywhere in the basin eventually flows past the river’s mouth.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12) · +1 more
drainage basin (watershed)English
All the land drained by a river and its tributaries, bounded by a divide.
Human Geography, Lesson 9.2 (grade 9–12)
All the land drained by a river and its tributaries, bounded by a divide.
Human Geography, Lesson 9.2 (grade 9–12)
drainage divide (watershed)English
The line on high ground that separates water flowing to one river system from water flowing to another. It does not always pass over the highest peaks.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
The line on high ground that separates water flowing to one river system from water flowing to another. It does not always pass over the highest peaks.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
dreadnoughtEnglish
A battleship on the pattern of HMS Dreadnought (1906), armed with many guns of one large caliber and driven by steam turbines; it made earlier battleships second-class almost overnight.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12) · Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
A battleship on the pattern of HMS Dreadnought (1906), armed with many guns of one large caliber and driven by steam turbines; it made earlier battleships second-class almost overnight.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12) · Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
dredgerEnglish
A machine, usually on a boat, that scoops mud and sand from the bottom of a waterway to deepen it.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.2 (grade 8)
A machine, usually on a boat, that scoops mud and sand from the bottom of a waterway to deepen it.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.2 (grade 8)
dredgingEnglish
Digging mud and sand from the bottom of a harbor or channel to make it deeper for ships.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
Digging mud and sand from the bottom of a harbor or channel to make it deeper for ships.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
drowned river valleyEnglish
A river valley flooded by the sea, leaving a deep inlet. The lower Hudson and New York Harbor are of this kind.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.4 (grade 8)
A river valley flooded by the sea, leaving a deep inlet. The lower Hudson and New York Harbor are of this kind.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.4 (grade 8)
dryness lineEnglish
In the Köppen system, the amount of yearly precipitation below which a place counts as dry (group B). It is higher for hotter places, because heat evaporates more water.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
In the Köppen system, the amount of yearly precipitation below which a place counts as dry (group B). It is higher for hotter places, because heat evaporates more water.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
dry-stone wallEnglish
A wall built of carefully fitted stones without mortar, as at Great Zimbabwe.
Grade 7 Geography: Regions of the World, Lesson 4.3 (grade 7)
A wall built of carefully fitted stones without mortar, as at Great Zimbabwe.
Grade 7 Geography: Regions of the World, Lesson 4.3 (grade 7)
dugoutEnglish
A home dug into the side of a hill or creek bank, with a front wall and roof of sod or logs.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.4 (grade 4)
A home dug into the side of a hill or creek bank, with a front wall and roof of sod or logs.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.4 (grade 4)
Dzungarian GateEnglish
A narrow, windy pass between mountains on today’s border of Kazakhstan and China, one of the main doors between the eastern and western steppe.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
A narrow, windy pass between mountains on today’s border of Kazakhstan and China, one of the main doors between the eastern and western steppe.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
E
earthEnglish
The great round world God made, where we live.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 2.1 (grade K)
The great round world God made, where we live.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 2.1 (grade K)
earth return (ground)English
Using the earth itself as the return half of the circuit, so a telegraph line needs only one wire instead of two.
Technology Overcoming Geography, Lesson 4.1 (grade 9–12)
Using the earth itself as the return half of the circuit, so a telegraph line needs only one wire instead of two.
Technology Overcoming Geography, Lesson 4.1 (grade 9–12)
earthen damEnglish
A dam built mostly of compacted earth and rock fill; the Gatun Dam across the Chagres created Gatun Lake.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
A dam built mostly of compacted earth and rock fill; the Gatun Dam across the Chagres created Gatun Lake.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
East EuropeEnglish
In Mackinder’s usage, the broad lands between Germany and Russia, from the Baltic to the Black Sea, which he saw as the gateway to the Heartland.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
In Mackinder’s usage, the broad lands between Germany and Russia, from the Baltic to the Black Sea, which he saw as the gateway to the Heartland.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
East Europe (Mackinder)English
In Mackinder’s 1919 book, the lands between Germany and Russia from the Baltic to the Black Sea, which he believed held the key to the Heartland.
Geopolitics: The Great Ideas, Lesson 5.3 (grade 9–12)
In Mackinder’s 1919 book, the lands between Germany and Russia from the Baltic to the Black Sea, which he believed held the key to the Heartland.
Geopolitics: The Great Ideas, Lesson 5.3 (grade 9–12)
East European PlainEnglish
The even larger lowland, often called the Russian Plain, that continues east from Poland across Belarus, Ukraine and European Russia to the Ural Mountains.
Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
The even larger lowland, often called the Russian Plain, that continues east from Poland across Belarus, Ukraine and European Russia to the Ural Mountains.
Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
echo soundingEnglish
Measuring the depth of water by sending a sound pulse down and timing how long it takes to bounce back from the bottom.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6)
Measuring the depth of water by sending a sound pulse down and timing how long it takes to bounce back from the bottom.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6)
ecological fallacyEnglish
The error of assuming that what is true of a group or an area as a whole is true of each individual or household in it.
Human Geography, Lesson 1.4 (grade 9–12)
The error of assuming that what is true of a group or an area as a whole is true of each individual or household in it.
Human Geography, Lesson 1.4 (grade 9–12)
economic developmentEnglish
A lasting rise in a country’s productive capacity and its people’s standard of living, usually measured by output per person, health, education and the shift of work out of farming.
Human Geography, Lesson 8.3 (grade 9–12)
A lasting rise in a country’s productive capacity and its people’s standard of living, usually measured by output per person, health, education and the shift of work out of farming.
Human Geography, Lesson 8.3 (grade 9–12)
ecumeneEnglish
The part of the earth’s land surface that is permanently lived on by people.
Human Geography, Lesson 2.1 (grade 9–12)
The part of the earth’s land surface that is permanently lived on by people.
Human Geography, Lesson 2.1 (grade 9–12)
edge cityEnglish
Journalist Joel Garreau’s term (1991) for a large concentration of offices and shopping that grows at a suburban highway junction, outside the old downtown (for example, Tysons, Virginia).
Human Geography, Lesson 7.4 (grade 9–12)
Journalist Joel Garreau’s term (1991) for a large concentration of offices and shopping that grows at a suburban highway junction, outside the old downtown (for example, Tysons, Virginia).
Human Geography, Lesson 7.4 (grade 9–12)
effective occupationEnglish
The rule, in the General Act, that a power claiming new territory on the African coast must notify the other signers and establish real authority there, not merely plant a flag.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
The rule, in the General Act, that a power claiming new territory on the African coast must notify the other signers and establish real authority there, not merely plant a flag.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
elevation gainEnglish
The total amount of climbing on a route, adding up every uphill part.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.4 (grade 6)
The total amount of climbing on a route, adding up every uphill part.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.4 (grade 6)
elevation profileEnglish
A side view of the land along a line, showing how high the ground is at each point. It shows at a glance whether a route climbs or runs level.
Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.4 (grade 5)
A side view of the land along a line, showing how high the ground is at each point. It shows at a glance whether a route climbs or runs level.
Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.4 (grade 5)
Ellis IslandEnglish
The federal immigration station in New York Harbor, open from 1892 to 1954, through which about 12 million immigrants passed.
Human Geography, Lesson 3.2 (grade 9–12)
The federal immigration station in New York Harbor, open from 1892 to 1954, through which about 12 million immigrants passed.
Human Geography, Lesson 3.2 (grade 9–12)
elongated stateEnglish
A country much longer than it is wide, such as Chile, Norway or Vietnam.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
A country much longer than it is wide, such as Chile, Norway or Vietnam.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
emergent layerEnglish
The scattered giant trees that poke up above the canopy into full sun and wind.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6)
The scattered giant trees that poke up above the canopy into full sun and wind.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6)
emigrantEnglish
A person who leaves one home to make a new home far away.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.4 (grade 2)
A person who leaves one home to make a new home far away.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.4 (grade 2)
empireEnglish
Many lands and peoples ruled by one ruler or one government.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.3 (grade 3)
Many lands and peoples ruled by one ruler or one government.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.3 (grade 3)
encirclement (pocket)English
Surrounding an enemy force by driving around both of its sides and closing the ring behind it, cutting it off from supply and retreat.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
Surrounding an enemy force by driving around both of its sides and closing the ring behind it, cutting it off from supply and retreat.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
enclaveEnglish
A piece of territory surrounded by another state or zone. West Berlin was a Western enclave deep inside the Soviet zone of Germany.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
A piece of territory surrounded by another state or zone. West Berlin was a Western enclave deep inside the Soviet zone of Germany.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
enclosed seaEnglish
A sea almost surrounded by land and joined to the ocean only by one or a few narrow straits, such as the Mediterranean and the Black Sea.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12)
A sea almost surrounded by land and joined to the ocean only by one or a few narrow straits, such as the Mediterranean and the Black Sea.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12)
end of trackEnglish
The very end of the line being built, where the newest rails were laid each day.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.2 (grade 4)
The very end of the line being built, where the newest rails were laid each day.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.2 (grade 4)
entrepôtEnglish
A trading city where goods are brought in, stored, sold and sent on to other markets.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12) · +3 more
A trading city where goods are brought in, stored, sold and sent on to other markets.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12) · +3 more
environmental determinismEnglish
The view that the physical environment, especially climate, fixes the character, abilities and history of peoples.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
The view that the physical environment, especially climate, fixes the character, abilities and history of peoples.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
envoyEnglish
A messenger sent by a ruler to speak for him to a foreign people or king.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12)
A messenger sent by a ruler to speak for him to a foreign people or king.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12)
equal-area mapEnglish
A map that keeps every land at its true size compared with the others, but bends or squashes shapes.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.4 (grade 5)
A map that keeps every land at its true size compared with the others, but bends or squashes shapes.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.4 (grade 5)
ergEnglish
A sand sea: a large area of wind-blown sand dunes. Ergs cover only about a fifth to a quarter of the Sahara.
Geography and History: Why Borders Fall Where They Do, Lesson 4.1 (grade 9–12)
A sand sea: a large area of wind-blown sand dunes. Ergs cover only about a fifth to a quarter of the Sahara.
Geography and History: Why Borders Fall Where They Do, Lesson 4.1 (grade 9–12)
error logEnglish
A record of every missed question with its topic and the cause of the miss, used to target the last weeks of review.
Human Geography, Lesson 10.4 (grade 9–12)
A record of every missed question with its topic and the cause of the miss, used to target the last weeks of review.
Human Geography, Lesson 10.4 (grade 9–12)
escarpmentEnglish
A long, steep slope or cliff at the edge of a plateau. Rivers that cross an escarpment drop in rapids and falls.
Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
A long, steep slope or cliff at the edge of a plateau. Rivers that cross an escarpment drop in rapids and falls.
Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
estuaryEnglish
A wide river mouth or bay where fresh river water mixes with salty ocean water. The Chesapeake Bay is the largest estuary in the United States.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
A wide river mouth or bay where fresh river water mixes with salty ocean water. The Chesapeake Bay is the largest estuary in the United States.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
ethnic religionEnglish
A religion closely tied to one people, land or culture, which does not actively seek converts from other peoples (Hinduism, Judaism, Shinto).
Human Geography, Lesson 4.3 (grade 9–12)
A religion closely tied to one people, land or culture, which does not actively seek converts from other peoples (Hinduism, Judaism, Shinto).
Human Geography, Lesson 4.3 (grade 9–12)
European Union (EU)English
A political and economic union of 27 European states (as of 2026), grown from the Coal and Steel Community of 1951 and the European Economic Community of 1957; created under its present name by the Maastricht Treaty (1992).
Human Geography, Lesson 5.4 (grade 9–12)
A political and economic union of 27 European states (as of 2026), grown from the Coal and Steel Community of 1951 and the European Economic Community of 1957; created under its present name by the Maastricht Treaty (1992).
Human Geography, Lesson 5.4 (grade 9–12)
EvergladesEnglish
A very wide, shallow, grassy wetland in southern Florida where water flows slowly south.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.2 (grade 2)
A very wide, shallow, grassy wetland in southern Florida where water flows slowly south.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.2 (grade 2)
exchange flowEnglish
Two currents moving opposite ways through a strait at different depths: lighter Atlantic water flows in on top and heavier, saltier Mediterranean water flows out beneath.
Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
Two currents moving opposite ways through a strait at different depths: lighter Atlantic water flows in on top and heavier, saltier Mediterranean water flows out beneath.
Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
exclaveEnglish
A piece of a country cut off from the rest of it by another country’s territory or by water, such as the Northwest Angle of Minnesota or Point Roberts, Washington.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
A piece of a country cut off from the rest of it by another country’s territory or by water, such as the Northwest Angle of Minnesota or Point Roberts, Washington.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
exclusive economic zone (EEZ)English
The sea area up to 200 nautical miles from a state’s coast in which it controls fishing, oil, gas and other resources, under the UN Convention on the Law of the Sea (1982).
Human Geography, Lesson 5.2 (grade 9–12)
The sea area up to 200 nautical miles from a state’s coast in which it controls fishing, oil, gas and other resources, under the UN Convention on the Law of the Sea (1982).
Human Geography, Lesson 5.2 (grade 9–12)
exotic riverEnglish
A river that rises in a rainy land and then flows through a desert, carrying water to a place that gets almost no rain of its own.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.1 (grade 8)
A river that rises in a rainy land and then flows through a desert, carrying water to a place that gets almost no rain of its own.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.1 (grade 8)
expansion diffusionEnglish
The spread of an idea or innovation outward while it stays strong at its source. Its forms are hierarchical (from larger or more important places to smaller ones), contagious (from person to person nearby) and stimulus (the underlying idea spreads, but the form changes).
Human Geography, Lesson 1.2 (grade 9–12)
The spread of an idea or innovation outward while it stays strong at its source. Its forms are hierarchical (from larger or more important places to smaller ones), contagious (from person to person nearby) and stimulus (the underlying idea spreads, but the form changes).
Human Geography, Lesson 1.2 (grade 9–12)
export-oriented industrializationEnglish
A development strategy of building industries that sell to world markets, as South Korea, Taiwan, Singapore and Hong Kong did from the 1960s.
Human Geography, Lesson 8.4 (grade 9–12)
A development strategy of building industries that sell to world markets, as South Korea, Taiwan, Singapore and Hong Kong did from the 1960s.
Human Geography, Lesson 8.4 (grade 9–12)
exposure and vulnerabilityEnglish
Exposure is how many people and things are in harm’s way; vulnerability is how easily they are harmed, depending on buildings, warning, wealth and preparation.
Human Geography, Lesson 9.4 (grade 9–12)
Exposure is how many people and things are in harm’s way; vulnerability is how easily they are harmed, depending on buildings, warning, wealth and preparation.
Human Geography, Lesson 9.4 (grade 9–12)
extensive agricultureEnglish
Farming that uses large areas of land with little labor and capital per acre (ranching, grazing).
Human Geography, Lesson 6.2 (grade 9–12)
Farming that uses large areas of land with little labor and capital per acre (ranching, grazing).
Human Geography, Lesson 6.2 (grade 9–12)
extent of territoryEnglish
For Mahan, not area in square miles but the length of coastline and number of harbors compared with the population available to use and defend them.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
For Mahan, not area in square miles but the length of coastline and number of harbors compared with the population available to use and defend them.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
eye and eyewallEnglish
The eye is the calm, often clear center of a hurricane. The eyewall is the ring of towering clouds around it, where the winds are strongest.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.3 (grade 6)
The eye is the calm, often clear center of a hurricane. The eyewall is the ring of towering clouds around it, where the winds are strongest.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.3 (grade 6)
F
falaj (plural aflaj)English
In Oman, a gently sloping channel, often partly underground, that carries water by gravity from a mountain source or aquifer to an oasis. The Persian form is called a qanat.
Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
In Oman, a gently sloping channel, often partly underground, that carries water by gravity from a mountain source or aquifer to an oasis. The Persian form is called a qanat.
Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
fall (autumn)English
The season after summer, when days get cooler and many leaves turn red, yellow and orange and drop to the ground.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.2 (grade K)
The season after summer, when days get cooler and many leaves turn red, yellow and orange and drop to the ground.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.2 (grade K)
falsifiableEnglish
Able to be shown false by some possible observation. Karl Popper argued that a scientific claim must be falsifiable.
Geopolitics: The Great Ideas, Lesson 1.5 (grade 9–12)
Able to be shown false by some possible observation. Karl Popper argued that a scientific claim must be falsifiable.
Geopolitics: The Great Ideas, Lesson 1.5 (grade 9–12)
farmEnglish
Land where people grow crops like wheat and corn or raise animals for food.
Grade 1 Geography: Maps and Journeys, Lesson 3.2 (grade 1) · Kindergarten Life Science: God Made the Animals, Lesson 9.3 (grade K)
Land where people grow crops like wheat and corn or raise animals for food.
Grade 1 Geography: Maps and Journeys, Lesson 3.2 (grade 1) · Kindergarten Life Science: God Made the Animals, Lesson 9.3 (grade K)
fatalismEnglish
The belief that everything is fixed in advance by impersonal fate (or by geography alone), so human choices make no real difference. It is not the biblical teaching of providence.
Geography and History: Why Borders Fall Where They Do, Lesson 1.5 (grade 9–12)
The belief that everything is fixed in advance by impersonal fate (or by geography alone), so human choices make no real difference. It is not the biblical teaching of providence.
Geography and History: Why Borders Fall Where They Do, Lesson 1.5 (grade 9–12)
fathomEnglish
A measure of water depth equal to 6 feet. “Mark twain” means two fathoms, or 12 feet.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
A measure of water depth equal to 6 feet. “Mark twain” means two fathoms, or 12 feet.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
federal stateEnglish
A state in which a written constitution divides power between a national government and regional governments (states, provinces, Länder or cantons), each with powers of its own, as in the United States, Canada, Germany and Switzerland.
Human Geography, Lesson 5.3 (grade 9–12)
A state in which a written constitution divides power between a national government and regional governments (states, provinces, Länder or cantons), each with powers of its own, as in the United States, Canada, Germany and Switzerland.
Human Geography, Lesson 5.3 (grade 9–12)
fire insurance mapEnglish
A map that showed which buildings were made of wood, brick or stone, so people could tell how easily each one might burn.
Grade 1 Geography: Maps and Journeys, Lesson 1.3 (grade 1)
A map that showed which buildings were made of wood, brick or stone, so people could tell how easily each one might burn.
Grade 1 Geography: Maps and Journeys, Lesson 1.3 (grade 1)
firefighterEnglish
The helper who puts out fires and rescues people in danger.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 6.2 (grade K)
The helper who puts out fires and rescues people in danger.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 6.2 (grade K)
first agricultural revolutionEnglish
The change from gathering and hunting to growing crops and herding animals; museum signs call it the Neolithic Revolution.
Human Geography, Lesson 6.1 (grade 9–12)
The change from gathering and hunting to growing crops and herding animals; museum signs call it the Neolithic Revolution.
Human Geography, Lesson 6.1 (grade 9–12)
fixed linkEnglish
A permanent bridge or tunnel across a strait, such as the Channel Tunnel, the Great Belt link or the Øresund Bridge.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
A permanent bridge or tunnel across a strait, such as the Channel Tunnel, the Great Belt link or the Øresund Bridge.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12)
flatboatEnglish
A big wooden box of a boat that floated downstream with the current carrying goods. It could not go back upstream, so it was taken apart and sold for lumber.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4) · Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12)
A big wooden box of a boat that floated downstream with the current carrying goods. It could not go back upstream, so it was taken apart and sold for lumber.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4) · Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12)
flight of locksEnglish
Several locks built one right after another, like a staircase, to climb a steep slope.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.2 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 8.3 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
Several locks built one right after another, like a staircase, to climb a steep slope.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.2 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 8.3 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
floeEnglish
A single flat piece of floating sea ice, from a few yards to miles across.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
A single flat piece of floating sea ice, from a few yards to miles across.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
flow mapEnglish
A map that shows movement with bands or arrows whose width is proportional to the amount moving, such as people, goods or troops.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
A map that shows movement with bands or arrows whose width is proportional to the amount moving, such as people, goods or troops.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
fluytEnglish
A Dutch cargo ship first built about 1595: long, roomy and cheap to sail with a small crew.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.2 (grade 8)
A Dutch cargo ship first built about 1595: long, roomy and cheap to sail with a small crew.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.2 (grade 8)
focus depthEnglish
How far below the surface an earthquake starts, measured in kilometers or miles.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
How far below the surface an earthquake starts, measured in kilometers or miles.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
fold mountainsEnglish
Mountains made when colliding plates squeeze, fold and stack layers of rock, as in the Himalaya and the Alps.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.3 (grade 6)
Mountains made when colliding plates squeeze, fold and stack layers of rock, as in the Himalaya and the Alps.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.3 (grade 6)
forced migrationEnglish
Movement in which people are compelled to leave or are carried away against their will, as in the Atlantic slave trade.
Human Geography, Lesson 3.2 (grade 9–12)
Movement in which people are compelled to leave or are carried away against their will, as in the Atlantic slave trade.
Human Geography, Lesson 3.2 (grade 9–12)
forestEnglish
A large piece of land covered with many trees growing close together.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.2 (grade 2)
A large piece of land covered with many trees growing close together.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.2 (grade 2)
Forest CantonsEnglish
Uri, Schwyz and Unterwalden, the mountain communities around Lake Lucerne whose 1291 alliance became the seed of Switzerland.
Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12)
Uri, Schwyz and Unterwalden, the mountain communities around Lake Lucerne whose 1291 alliance became the seed of Switzerland.
Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12)
forgeryEnglish
A fake made to fool people into thinking it is genuine and old.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
A fake made to fool people into thinking it is genuine and old.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
formal regionEnglish
A region marked by a shared feature that can be mapped, such as one language, one climate, one river basin or one country.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
A region marked by a shared feature that can be mapped, such as one language, one climate, one river basin or one country.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
forty-ninersEnglish
The gold-seekers who rushed to California in 1849.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.3 (grade 4)
The gold-seekers who rushed to California in 1849.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.3 (grade 4)
forward and backEnglish
Forward is the way your face looks. Back is the way behind you.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.3 (grade K)
Forward is the way your face looks. Back is the way behind you.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.3 (grade K)
forward capitalEnglish
A capital placed toward a country’s interior or frontier to draw people, roads and trade into lands that were thinly settled.
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
A capital placed toward a country’s interior or frontier to draw people, roads and trade into lands that were thinly settled.
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
foulingEnglish
The growth of weed, barnacles and other sea life on a ship’s bottom, which slows it down. Iron hulls fouled badly in warm seas.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
The growth of weed, barnacles and other sea life on a ship’s bottom, which slows it down. Iron hulls fouled badly in warm seas.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
founder cropsEnglish
The first crops domesticated in the Fertile Crescent: emmer wheat, einkorn wheat, barley, lentils, peas, chickpeas, bitter vetch and flax.
Human Geography, Lesson 6.1 (grade 9–12)
The first crops domesticated in the Fertile Crescent: emmer wheat, einkorn wheat, barley, lentils, peas, chickpeas, bitter vetch and flax.
Human Geography, Lesson 6.1 (grade 9–12)
free portEnglish
A port where merchants may land, store and ship goods without paying customs duties (taxes on imports and exports).
Grade 7 Geography: Regions of the World, Lesson 7.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.3 (grade 9–12)
A port where merchants may land, store and ship goods without paying customs duties (taxes on imports and exports).
Grade 7 Geography: Regions of the World, Lesson 7.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.3 (grade 9–12)
freightEnglish
Goods carried from one place to another to be sold, such as flour, lumber, salt or cloth.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.1 (grade 4)
Goods carried from one place to another to be sold, such as flour, lumber, salt or cloth.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.1 (grade 4)
freight rateEnglish
The price a shipper pays to carry cargo from one port to another.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.2 (grade 8)
The price a shipper pays to carry cargo from one port to another.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.2 (grade 8)
fresh waterEnglish
Water that is not salty. Rivers and most lakes have fresh water.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.2 (grade K) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.3 (grade K) · Grade 2 Life Science: Animal Families, Lesson 5.4 (grade 2)
Water that is not salty. Rivers and most lakes have fresh water.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.2 (grade K) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.3 (grade K) · Grade 2 Life Science: Animal Families, Lesson 5.4 (grade 2)
freshwaterEnglish
Water that is not salty, like the water in most lakes and rivers.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
Water that is not salty, like the water in most lakes and rivers.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
friction of distanceEnglish
The idea that every extra mile adds cost, time or effort, so that contact and trade fall off with distance.
Technology Overcoming Geography, Lesson 5.4 (grade 9–12)
The idea that every extra mile adds cost, time or effort, so that contact and trade fall off with distance.
Technology Overcoming Geography, Lesson 5.4 (grade 9–12)
from aboveEnglish
Looking straight down from high up, the way a bird sees the ground.
Grade 1 Geography: Maps and Journeys, Lesson 1.1 (grade 1)
Looking straight down from high up, the way a bird sees the ground.
Grade 1 Geography: Maps and Journeys, Lesson 1.1 (grade 1)
frontierEnglish
The edge of settled land, beyond which few settlers lived.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4) · Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12) · Human Geography, Lesson 3.3 (grade 9–12)
The edge of settled land, beyond which few settlers lived.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4) · Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12) · Human Geography, Lesson 3.3 (grade 9–12)
frontier (Latin limes)English
The edge zone of a state or empire, often guarded by forts and roads. Rome’s fortified frontier was called the limes.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
The edge zone of a state or empire, often guarded by forts and roads. Rome’s fortified frontier was called the limes.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
frost wedgingEnglish
Mechanical weathering in which water freezes in a crack, swells by about 9 percent and pries the rock apart.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.1 (grade 6)
Mechanical weathering in which water freezes in a crack, swells by about 9 percent and pries the rock apart.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.1 (grade 6)
frozen conflictEnglish
A war that has stopped fighting without a peace treaty, leaving borders unsettled, as in Abkhazia and South Ossetia.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
A war that has stopped fighting without a peace treaty, leaving borders unsettled, as in Abkhazia and South Ossetia.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
functional regionEnglish
A region tied together by movement and connection to a center or a route, such as the area served by a port, a railway or a strait.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
A region tied together by movement and connection to a center or a route, such as the area served by a port, a railway or a strait.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
G
gate (gap)English
A narrow passage between basins, such as the gap near Vienna and Bratislava. Whoever holds a gate controls movement through it.
Geography and History: Why Borders Fall Where They Do, Lesson 2.2 (grade 9–12)
A narrow passage between basins, such as the gap near Vienna and Bratislava. Whoever holds a gate controls movement through it.
Geography and History: Why Borders Fall Where They Do, Lesson 2.2 (grade 9–12)
gateway cityEnglish
A city that controls the entrance to a large region, so that people and goods going into or out of that region pass through it.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.2 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.1 (grade 8)
A city that controls the entrance to a large region, so that people and goods going into or out of that region pass through it.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.2 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.1 (grade 8)
gateway portEnglish
A port where most cargo enters or leaves the surrounding country by truck, rail or barge.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8)
A port where most cargo enters or leaves the surrounding country by truck, rail or barge.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8)
Gatún LakeEnglish
The large artificial lake formed when the Gatún Dam blocked the Chagres River. Its surface is about 26 m (85 ft) above sea level, and ships cross it in the middle of the canal.
Grade 7 Geography: Regions of the World, Lesson 8.3 (grade 7)
The large artificial lake formed when the Gatún Dam blocked the Chagres River. Its surface is about 26 m (85 ft) above sea level, and ships cross it in the middle of the canal.
Grade 7 Geography: Regions of the World, Lesson 8.3 (grade 7)
GDP per capita (PPP)English
Gross domestic product, the value of all final goods and services produced in a country in a year, divided by its population. At purchasing power parity it is adjusted for what money actually buys in that country.
Human Geography, Lesson 8.3 (grade 9–12)
Gross domestic product, the value of all final goods and services produced in a country in a year, divided by its population. At purchasing power parity it is adjusted for what money actually buys in that country.
Human Geography, Lesson 8.3 (grade 9–12)
General Act of BerlinEnglish
The agreement signed February 26, 1885, at the end of the Berlin Conference. It set rules for free trade and navigation in the Congo and Niger basins, for claiming new coasts, and against the slave trade.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
The agreement signed February 26, 1885, at the end of the Berlin Conference. It set rules for free trade and navigation in the Congo and Niger basins, for claiming new coasts, and against the slave trade.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
genre de vieEnglish
French for “way of life”: Vidal de la Blache’s term for the habits, tools and customs by which a people uses its land.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12)
French for “way of life”: Vidal de la Blache’s term for the habits, tools and customs by which a people uses its land.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12)
geocacheEnglish
A small container hidden for others to find using posted GPS coordinates.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
A small container hidden for others to find using posted GPS coordinates.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
geographerEnglish
A person who studies the earth and its places and makes maps.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.2 (grade K)
A person who studies the earth and its places and makes maps.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.2 (grade K)
geographic determinismEnglish
The belief that geography fixes the course of history. Spykman denied being a determinist; his critics said his theory leaned that way.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
The belief that geography fixes the course of history. Spykman denied being a determinist; his critics said his theory leaned that way.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
geographical positionEnglish
Mahan’s first element: where a nation lies relative to the sea, its rivals and the great trade routes, including whether it must also defend land frontiers.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
Mahan’s first element: where a nation lies relative to the sea, its rivals and the great trade routes, including whether it must also defend land frontiers.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
geographyEnglish
The study of the earth and where things are on it. Ptolemy’s book Geography was a guide to drawing the whole known world.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.1 (grade 5) · Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
The study of the earth and where things are on it. Ptolemy’s book Geography was a guide to drawing the whole known world.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.1 (grade 5) · Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
geometric (artificial) boundaryEnglish
A border drawn as a straight line or along a parallel of latitude or a meridian of longitude, without regard to the land beneath it.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
A border drawn as a straight line or along a parallel of latitude or a meridian of longitude, without regard to the land beneath it.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
geometric borderEnglish
A boundary that follows a line of latitude or longitude or a straight line between points, such as the 49th parallel or the Mason–Dixon Line.
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
A boundary that follows a line of latitude or longitude or a straight line between points, such as the 49th parallel or the Mason–Dixon Line.
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
geometric boundaryEnglish
A border drawn as a straight line, an arc, or along a parallel or meridian, without regard to the land. Also called an artificial or astronomical boundary.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12) · Human Geography, Lesson 5.2 (grade 9–12)
A border drawn as a straight line, an arc, or along a parallel or meridian, without regard to the land. Also called an artificial or astronomical boundary.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12) · Human Geography, Lesson 5.2 (grade 9–12)
geometric (exponential) growthEnglish
Growth by a constant multiple in each period, as 1, 2, 4, 8, 16. Malthus said population, when unchecked, grows this way.
Human Geography, Lesson 2.3 (grade 9–12)
Growth by a constant multiple in each period, as 1, 2, 4, 8, 16. Malthus said population, when unchecked, grows this way.
Human Geography, Lesson 2.3 (grade 9–12)
geopoliticsEnglish
The study of how geography (location, size, terrain, resources, routes and distance) shapes the power, fears and choices of states.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12)
The study of how geography (location, size, terrain, resources, routes and distance) shapes the power, fears and choices of states.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12)
GeopolitikEnglish
The German school of geopolitics of the 1920s to 1940s, led by Karl Haushofer, which mixed geography with the political aim of overturning the 1919 peace settlement.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
The German school of geopolitics of the 1920s to 1940s, led by Karl Haushofer, which mixed geography with the political aim of overturning the 1919 peace settlement.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
georeferencingEnglish
Matching points on an old map to their true locations so that a computer can stretch the old map to lie exactly over a modern one.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
Matching points on an old map to their true locations so that a computer can stretch the old map to lie exactly over a modern one.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
Georgian Military RoadEnglish
The road of about 130 miles (208 km) from Vladikavkaz over the Jvari (Cross) Pass to Tbilisi, rebuilt by the Russian army in the 1800s to hold Georgia.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
The road of about 130 miles (208 km) from Vladikavkaz over the Jvari (Cross) Pass to Tbilisi, rebuilt by the Russian army in the 1800s to hold Georgia.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
ghatEnglish
In railway and road building in India, a steep mountain pass, especially across the Western Ghats; the word also means steps leading down to a river.
Grade 7 Geography: Regions of the World, Lesson 5.3 (grade 7)
In railway and road building in India, a steep mountain pass, especially across the Western Ghats; the word also means steps leading down to a river.
Grade 7 Geography: Regions of the World, Lesson 5.3 (grade 7)
giant sequoiaEnglish
A huge evergreen tree that grows wild only in the Sierra Nevada mountains of California. It is the biggest kind of tree in the world.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.2 (grade 2)
A huge evergreen tree that grows wild only in the Sierra Nevada mountains of California. It is the biggest kind of tree in the world.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.2 (grade 2)
GIS (geographic information system)English
A computer system that stores maps as layers of data tied to real places, so they can be stacked, searched, measured and compared.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.4 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
A computer system that stores maps as layers of data tied to real places, so they can be stacked, searched, measured and compared.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.4 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
globalizationEnglish
The growing connection of places worldwide through trade, travel, communication and investment, so that events at one scale affect others.
Human Geography, Lesson 1.4 (grade 9–12)
The growing connection of places worldwide through trade, travel, communication and investment, so that events at one scale affect others.
Human Geography, Lesson 1.4 (grade 9–12)
glocalizationEnglish
Adapting a global product or idea to local customs and tastes, as when a worldwide restaurant chain changes its menu country by country.
Human Geography, Lesson 1.4 (grade 9–12)
Adapting a global product or idea to local customs and tastes, as when a worldwide restaurant chain changes its menu country by country.
Human Geography, Lesson 1.4 (grade 9–12)
gnomonic projectionEnglish
A map projection on which every great circle appears as a straight line, used to plan the shortest routes, especially near the poles.
Technology Overcoming Geography, Lesson 4.4 (grade 9–12)
A map projection on which every great circle appears as a straight line, used to plan the shortest routes, especially near the poles.
Technology Overcoming Geography, Lesson 4.4 (grade 9–12)
GNSSEnglish
Global Navigation Satellite System, the general name for GPS and its counterparts: Russia’s GLONASS, Europe’s Galileo and China’s BeiDou.
Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
Global Navigation Satellite System, the general name for GPS and its counterparts: Russia’s GLONASS, Europe’s Galileo and China’s BeiDou.
Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
gold rushEnglish
A sudden rush of many people to a place where gold has been found.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.3 (grade 4)
A sudden rush of many people to a place where gold has been found.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.3 (grade 4)
golden spikeEnglish
A special spike made of gold, set in the last tie to celebrate the joining of the two railroads.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.2 (grade 2)
A special spike made of gold, set in the last tie to celebrate the joining of the two railroads.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.2 (grade 2)
goreEnglish
A pointed strip of map, wide at the equator and narrow at the poles. Glued side by side on a ball, gores make a globe.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.4 (grade 5)
A pointed strip of map, wide at the equator and narrow at the poles. Glued side by side on a ball, gores make a globe.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.4 (grade 5)
GPSEnglish
The Global Positioning System, a group of U.S. satellites whose timed radio signals let a receiver anywhere on Earth find its position, height and the exact time.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8)
The Global Positioning System, a group of U.S. satellites whose timed radio signals let a receiver anywhere on Earth find its position, height and the exact time.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8)
GPS (Global Positioning System)English
The U.S. satellite navigation system: a constellation of about 31 working satellites, ground control stations and the receivers in phones, ships, cars and aircraft.
Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
The U.S. satellite navigation system: a constellation of about 31 working satellites, ground control stations and the receivers in phones, ships, cars and aircraft.
Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
gradient (grade)English
How steep a road or railway is, often given as a percent: a 2% grade rises 2 m for every 100 m of distance.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7) · Technology Overcoming Geography, Lesson 2.3 (grade 9–12)
How steep a road or railway is, often given as a percent: a 2% grade rises 2 m for every 100 m of distance.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7) · Technology Overcoming Geography, Lesson 2.3 (grade 9–12)
grain tributeEnglish
Tax grain, mostly rice, that the provinces of the south shipped north to feed the capital and the army.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7)
Tax grain, mostly rice, that the provinces of the south shipped north to feed the capital and the army.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7)
Grande ArméeEnglish
Napoleon’s “Great Army,” the multinational force of French, Polish, German, Italian and other troops that invaded Russia in 1812.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
Napoleon’s “Great Army,” the multinational force of French, Polish, German, Italian and other troops that invaded Russia in 1812.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
grapnelEnglish
A hooked iron grappling tool dragged along the sea floor on a long rope to catch and lift a lost cable.
Technology Overcoming Geography, Lesson 4.2 (grade 9–12)
A hooked iron grappling tool dragged along the sea floor on a long rope to catch and lift a lost cable.
Technology Overcoming Geography, Lesson 4.2 (grade 9–12)
grasslandEnglish
A biome covered mostly by grasses and flowers, with few trees, where rain is too scanty or uncertain for forest. In North America it is called prairie; in Eurasia, steppe.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.2 (grade 6)
A biome covered mostly by grasses and flowers, with few trees, where rain is too scanty or uncertain for forest. In North America it is called prairie; in Eurasia, steppe.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.2 (grade 6)
gravity modelEnglish
A model that predicts the interaction between two places as proportional to the product of their populations divided by the square of the distance between them: P₁ × P₂ ÷ d².
Human Geography, Lesson 1.2 (grade 9–12) · Human Geography, Lesson 10.1 (grade 9–12) · Human Geography, Lesson 4.4 (grade 9–12) · +2 more
A model that predicts the interaction between two places as proportional to the product of their populations divided by the square of the distance between them: P₁ × P₂ ÷ d².
Human Geography, Lesson 1.2 (grade 9–12) · Human Geography, Lesson 10.1 (grade 9–12) · Human Geography, Lesson 4.4 (grade 9–12) · +2 more
Great ArcEnglish
The chain of triangles run north along a meridian near 78° E, from the southern tip of India to the Himalayan foothills, to measure the length of a degree of latitude and the shape of the earth.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12)
The chain of triangles run north along a meridian near 78° E, from the southern tip of India to the Himalayan foothills, to measure the length of a degree of latitude and the shape of the earth.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12)
Great Dividing RangeEnglish
The long belt of mountains and high plateaus, about 3,500 km (2,200 miles) long, that runs down eastern Australia near the coast.
Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
The long belt of mountains and high plateaus, about 3,500 km (2,200 miles) long, that runs down eastern Australia near the coast.
Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
Great LakesEnglish
Five huge lakes of fresh water in the northern Midwest: Superior, Michigan, Huron, Erie and Ontario.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.3 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
Five huge lakes of fresh water in the northern Midwest: Superior, Michigan, Huron, Erie and Ontario.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.3 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
Great White FleetEnglish
The popular name for the sixteen U.S. battleships, painted white with buff trim, that steamed around the world from December 16, 1907, to February 22, 1909.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
The popular name for the sixteen U.S. battleships, painted white with buff trim, that steamed around the world from December 16, 1907, to February 22, 1909.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
Greater CaucasusEnglish
The main range of the Caucasus, running about 750 miles (1,200 km) from the Black Sea to the Caspian Sea.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
The main range of the Caucasus, running about 750 miles (1,200 km) from the Black Sea to the Caspian Sea.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
Green Revolution (third agricultural revolution)English
The spread, mainly from the 1960s, of high-yielding semi-dwarf wheat and rice together with fertilizer, irrigation and pest control to developing countries; the name was coined by William Gaud in 1968.
Human Geography, Lesson 6.3 (grade 9–12)
The spread, mainly from the 1960s, of high-yielding semi-dwarf wheat and rice together with fertilizer, irrigation and pest control to developing countries; the name was coined by William Gaud in 1968.
Human Geography, Lesson 6.3 (grade 9–12)
greenbeltEnglish
A ring of land around a city where building is restricted, to limit outward growth and keep farms and open country nearby.
Human Geography, Lesson 9.3 (grade 9–12)
A ring of land around a city where building is restricted, to limit outward growth and keep farms and open country nearby.
Human Geography, Lesson 9.3 (grade 9–12)
GreenwichEnglish
A town on the River Thames, now part of London, where the Royal Observatory stands on the prime meridian. Say it “GREN-itch.”
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 1.3 (grade 3)
A town on the River Thames, now part of London, where the Royal Observatory stands on the prime meridian. Say it “GREN-itch.”
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 1.3 (grade 3)
Greenwich timeEnglish
The time at the prime meridian in Greenwich, England. A ship’s chronometer was set to it before the voyage.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.3 (grade 5)
The time at the prime meridian in Greenwich, England. A ship’s chronometer was set to it before the voyage.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.3 (grade 5)
grid navigationEnglish
A method used near the poles in which navigators steer by a grid of parallel lines laid over the chart and a gyroscope, instead of by meridians and a magnetic compass, which become useless there.
Technology Overcoming Geography, Lesson 4.4 (grade 9–12)
A method used near the poles in which navigators steer by a grid of parallel lines laid over the chart and a gyroscope, instead of by meridians and a magnetic compass, which become useless there.
Technology Overcoming Geography, Lesson 4.4 (grade 9–12)
grid planEnglish
A town plan in which main streets run in straight lines and cross at right angles, dividing the town into blocks.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
A town plan in which main streets run in straight lines and cross at right angles, dividing the town into blocks.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
grid referenceEnglish
The letter and number that name one square of a grid, such as D3.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.2 (grade 4)
The letter and number that name one square of a grid, such as D3.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.2 (grade 4)
ground trackEnglish
The path on the earth’s surface directly beneath a satellite. Because the earth turns, each orbit’s ground track lands farther west.
Technology Overcoming Geography, Lesson 5.1 (grade 9–12)
The path on the earth’s surface directly beneath a satellite. Because the earth turns, each orbit’s ground track lands farther west.
Technology Overcoming Geography, Lesson 5.1 (grade 9–12)
guest workerEnglish
A foreign worker admitted for a limited time to fill labor needs, usually without a direct path to citizenship, as in West Germany’s program from 1955 or the U.S. Bracero Program (1942–1964).
Human Geography, Lesson 3.4 (grade 9–12)
A foreign worker admitted for a limited time to fill labor needs, usually without a direct path to citizenship, as in West Germany’s program from 1955 or the U.S. Bracero Program (1942–1964).
Human Geography, Lesson 3.4 (grade 9–12)
guiding questionEnglish
The one question a capstone paper sets out to answer. It decides the edges of the region, which maps are needed and which facts matter.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
The one question a capstone paper sets out to answer. It decides the edges of the region, which maps are needed and which facts matter.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
gulfEnglish
A big part of the ocean that reaches into the land. The Mississippi flows into the Gulf of Mexico.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.1 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.3 (grade 3)
A big part of the ocean that reaches into the land. The Mississippi flows into the Gulf of Mexico.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.1 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.3 (grade 3)
Gulf CoastEnglish
The coast of the United States along the Gulf of Mexico, from Florida to Texas.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.4 (grade 4)
The coast of the United States along the Gulf of Mexico, from Florida to Texas.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.4 (grade 4)
H
Haber–Bosch processEnglish
The industrial method of making ammonia from the nitrogen of the air (Haber 1909; Bosch’s factory 1913), the basis of synthetic nitrogen fertilizer.
Human Geography, Lesson 6.3 (grade 9–12)
The industrial method of making ammonia from the nitrogen of the air (Haber 1909; Bosch’s factory 1913), the basis of synthetic nitrogen fertilizer.
Human Geography, Lesson 6.3 (grade 9–12)
haijinEnglish
“Sea ban”: Ming laws restricting private Chinese overseas trade and sea travel, enforced at different strengths from the 1370s to the 1560s.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
“Sea ban”: Ming laws restricting private Chinese overseas trade and sea travel, enforced at different strengths from the 1370s to the 1560s.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
hajjEnglish
The pilgrimage to Mecca that Islam asks every Muslim who is able to make once in a lifetime.
Grade 7 Geography: Regions of the World, Lesson 4.3 (grade 7) · Human Geography, Lesson 4.4 (grade 9–12)
The pilgrimage to Mecca that Islam asks every Muslim who is able to make once in a lifetime.
Grade 7 Geography: Regions of the World, Lesson 4.3 (grade 7) · Human Geography, Lesson 4.4 (grade 9–12)
haliteEnglish
The mineral name for rock salt (sodium chloride) found in thick beds underground, left where salty water once dried away.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
The mineral name for rock salt (sodium chloride) found in thick beds underground, left where salty water once dried away.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
handrailEnglish
A long feature such as a trail, fence, stream or edge of a field that you can follow toward your goal.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
A long feature such as a trail, fence, stream or edge of a field that you can follow toward your goal.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
hanging valleyEnglish
A smaller side valley left high above a deeper glacial valley, often with a waterfall pouring from its mouth.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.4 (grade 6)
A smaller side valley left high above a deeper glacial valley, often with a waterfall pouring from its mouth.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.4 (grade 6)
Harappan civilizationEnglish
The Bronze Age civilization of the Indus valley, about 2600–1900 B.C. at its height, named after Harappa, the first of its cities to be studied.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
The Bronze Age civilization of the Indus valley, about 2600–1900 B.C. at its height, named after Harappa, the first of its cities to be studied.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.3 (grade 8)
head of navigationEnglish
The farthest point up a river that ships can sail before falls or shallow water stop them.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
The farthest point up a river that ships can sail before falls or shallow water stop them.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
headlandEnglish
A high point of land that sticks out into the sea, like a cape.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5)
A high point of land that sticks out into the sea, like a cape.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5)
headwatersEnglish
The small streams and springs where a river begins.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.1 (grade 4)
The small streams and springs where a river begins.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.1 (grade 4)
HeartlandEnglish
Mackinder’s 1919 name for the enlarged pivot area: the interior of Eurasia that sea power cannot reach, now extended west to include East Europe, the Baltic and Black Sea basins, and south to Tibet, Mongolia and Persia.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
Mackinder’s 1919 name for the enlarged pivot area: the interior of Eurasia that sea power cannot reach, now extended west to include East Europe, the Baltic and Black Sea basins, and south to Tibet, Mongolia and Persia.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
heat capacityEnglish
How much heat something must take in to warm up. Water has a very high heat capacity, so it warms and cools slowly.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
How much heat something must take in to warm up. Water has a very high heat capacity, so it warms and cools slowly.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
heat pipeEnglish
A sealed pipe filled with a fluid that carries heat up out of the ground and lets it escape into cold air, keeping the ground frozen.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
A sealed pipe filled with a fluid that carries heat up out of the ground and lets it escape into cold air, keeping the ground frozen.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
heated shotEnglish
Iron cannon balls heated red-hot in furnaces before firing so they would set wooden ships on fire; used by the Gibraltar garrison in 1782.
Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
Iron cannon balls heated red-hot in furnaces before firing so they would set wooden ships on fire; used by the Gibraltar garrison in 1782.
Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
HejazEnglish
The western strip of Arabia along the Red Sea, with its mountains and the towns of Mecca, Medina and Taif.
Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
The western strip of Arabia along the Red Sea, with its mountains and the towns of Mecca, Medina and Taif.
Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
helotsEnglish
The unfree people of Laconia and Messenia, owned by the Spartan state and forced to work the land for Spartan citizens.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12)
The unfree people of Laconia and Messenia, owned by the Spartan state and forced to work the land for Spartan citizens.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12)
Hexi CorridorEnglish
A narrow strip of oases, about 1,000 km (600 miles) long, between the Qilian Mountains and the Gobi, which forms China’s gateway to the west (also called the Gansu Corridor).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12)
A narrow strip of oases, about 1,000 km (600 miles) long, between the Qilian Mountains and the Gobi, which forms China’s gateway to the west (also called the Gansu Corridor).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12)
Hexi (Gansu) CorridorEnglish
A narrow strip of oases between the Qilian Mountains and the Gobi Desert that connected China with Central Asia; Han and Ming walls guarded it.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
A narrow strip of oases between the Qilian Mountains and the Gobi Desert that connected China with Central Asia; Han and Ming walls guarded it.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
hidden assumptionEnglish
An unstated belief on which an argument depends, such as an assumption about technology or about what an enemy will choose.
Geopolitics: The Great Ideas, Lesson 1.5 (grade 9–12)
An unstated belief on which an argument depends, such as an assumption about technology or about what an enemy will choose.
Geopolitics: The Great Ideas, Lesson 1.5 (grade 9–12)
hierarchical diffusionEnglish
Spread from one important place or person to others of similar rank first: from city to city, or from a ruler to his people.
Human Geography, Lesson 4.2 (grade 9–12)
Spread from one important place or person to others of similar rank first: from city to city, or from a ruler to his people.
Human Geography, Lesson 4.2 (grade 9–12)
high islandEnglish
A Pacific island made by a volcano, with mountains, streams and rich soil, such as Tahiti or the islands of Hawaiʻi.
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
A Pacific island made by a volcano, with mountains, streams and rich soil, such as Tahiti or the islands of Hawaiʻi.
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
high tide and low tideEnglish
The highest and lowest water levels reached during one rise and fall of the tide.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.3 (grade 6)
The highest and lowest water levels reached during one rise and fall of the tide.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.3 (grade 6)
HimalayaEnglish
The highest mountain range on earth, an arc about 2,400 km (1,500 mi) long across the north of South Asia; the name means “abode of snow” in Sanskrit.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
The highest mountain range on earth, an arc about 2,400 km (1,500 mi) long across the north of South Asia; the name means “abode of snow” in Sanskrit.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
hinterlandEnglish
The inland region a port serves, the area that sends exports through it and receives its imports.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 1.4 (grade 7) · +3 more
The inland region a port serves, the area that sends exports through it and receives its imports.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 1.4 (grade 7) · +3 more
historical atlasEnglish
A bound collection of maps showing places as they were at past dates, usually arranged so that changes over time can be compared.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12)
A bound collection of maps showing places as they were at past dates, usually arranged so that changes over time can be compared.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12)
hogging and saggingEnglish
The bending of a long hull when it is supported by a wave in the middle (hogging, the ends droop) or at the two ends (sagging, the middle droops). Wooden hulls could not grow much longer than about 90 m (300 ft) because of it.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
The bending of a long hull when it is supported by a wave in the middle (hogging, the ends droop) or at the two ends (sagging, the middle droops). Wooden hulls could not grow much longer than about 90 m (300 ft) because of it.
Technology Overcoming Geography, Lesson 1.5 (grade 9–12)
homeEnglish
The place where my family lives. I can find it on a map and a globe.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.4 (grade K)
The place where my family lives. I can find it on a map and a globe.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.4 (grade K)
homelandEnglish
The place where an animal lives and finds its food, water and shelter.
Grade 1 Geography: Maps and Journeys, Lesson 7.1 (grade 1)
The place where an animal lives and finds its food, water and shelter.
Grade 1 Geography: Maps and Journeys, Lesson 7.1 (grade 1)
homesteaderEnglish
A person who claimed land under the Homestead Act and settled on it.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.4 (grade 4)
A person who claimed land under the Homestead Act and settled on it.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.4 (grade 4)
horizontal scaleEnglish
How much real distance across the ground each unit of the model or map stands for.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6)
How much real distance across the ground each unit of the model or map stands for.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6)
hostageEnglish
A person held by one side until the other side does what is demanded, such as returning a stolen boat.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
A person held by one side until the other side does what is demanded, such as returning a stolen boat.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
hot springEnglish
A pool or stream of water that comes up from the ground already heated by hot rock below.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.1 (grade 4)
A pool or stream of water that comes up from the ground already heated by hot rock below.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.1 (grade 4)
hub-and-spoke networkEnglish
A pattern of routes in which many places connect through one central hub instead of each being linked directly to all the others.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8)
A pattern of routes in which many places connect through one central hub instead of each being linked directly to all the others.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8)
Human Development Index (HDI)English
A summary measure published by the United Nations Development Programme since 1990 that combines life expectancy, years of schooling and income per person into one number between 0 and 1.
Human Geography, Lesson 8.3 (grade 9–12)
A summary measure published by the United Nations Development Programme since 1990 that combines life expectancy, years of schooling and income per person into one number between 0 and 1.
Human Geography, Lesson 8.3 (grade 9–12)
human–environment interactionEnglish
The two-way relationship between people and the physical world: how land, water and climate shape human life, and how people change the land.
Human Geography, Lesson 10.4 (grade 9–12)
The two-way relationship between people and the physical world: how land, water and climate shape human life, and how people change the land.
Human Geography, Lesson 10.4 (grade 9–12)
Humboldt CurrentEnglish
A cold ocean current that flows north along the coasts of Chile and Peru. It cools the air above it so that little rain falls, helping make the Atacama one of the driest deserts on earth, and it feeds rich fisheries.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
A cold ocean current that flows north along the coasts of Chile and Peru. It cools the air above it so that little rain falls, helping make the Atacama one of the driest deserts on earth, and it feeds rich fisheries.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
I
ice capEnglish
A thick sheet of ice covering land all year, such as the ice sheets of Greenland and Antarctica.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
A thick sheet of ice covering land all year, such as the ice sheets of Greenland and Antarctica.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
ice shelfEnglish
A huge, thick sheet of ice that flows off the land and floats on the sea. Amundsen built his base on the Ross Ice Shelf.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5)
A huge, thick sheet of ice that flows off the land and floats on the sea. Amundsen built his base on the Ross Ice Shelf.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5)
icebreakerEnglish
A ship with a strong, sloping bow and powerful engines that rides up onto sea ice and breaks it under its weight, opening a channel for other ships.
Grade 7 Geography: Regions of the World, Lesson 2.2 (grade 7)
A ship with a strong, sloping bow and powerful engines that rides up onto sea ice and breaks it under its weight, opening a channel for other ships.
Grade 7 Geography: Regions of the World, Lesson 2.2 (grade 7)
immigration policyEnglish
The laws and rules by which a country decides who may enter, how many, for how long, and on what path to citizenship.
Human Geography, Lesson 3.4 (grade 9–12)
The laws and rules by which a country decides who may enter, how many, for how long, and on what path to citizenship.
Human Geography, Lesson 3.4 (grade 9–12)
immunityEnglish
The body’s power to fight off a disease, often built up after people have met that disease before.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5) · Grade 5 Life Science: The Human Body, Lesson 8.1 (grade 5)
The body’s power to fight off a disease, often built up after people have met that disease before.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5) · Grade 5 Life Science: The Human Body, Lesson 8.1 (grade 5)
imperial frontierEnglish
The edge of an empire, where its power meets another empire or peoples it does not yet rule.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
The edge of an empire, where its power meets another empire or peoples it does not yet rule.
Geography and History: Why Borders Fall Where They Do, Lesson 3.5 (grade 9–12)
import substitution industrialization (ISI)English
A development strategy of using tariffs and quotas to block imports so that home factories will grow up to replace them.
Human Geography, Lesson 8.4 (grade 9–12)
A development strategy of using tariffs and quotas to block imports so that home factories will grow up to replace them.
Human Geography, Lesson 8.4 (grade 9–12)
in-between landsEnglish
Lands that are not hot all year and not icy all year. They have four seasons. Mapmakers call them temperate.
Grade 1 Geography: Maps and Journeys, Lesson 5.3 (grade 1)
Lands that are not hot all year and not icy all year. They have four seasons. Mapmakers call them temperate.
Grade 1 Geography: Maps and Journeys, Lesson 5.3 (grade 1)
in-between placesEnglish
Places between the equator and the poles. They have a warm summer and a cold winter, like most of America.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.3 (grade K)
Places between the equator and the poles. They have a warm summer and a cold winter, like most of America.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.3 (grade K)
IncaEnglish
A people of the Andes whose rulers built a great empire there in the 1400s, with its capital at Cusco in Peru.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.3 (grade 3)
A people of the Andes whose rulers built a great empire there in the 1400s, with its capital at Cusco in Peru.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.3 (grade 3)
inchEnglish
A small length, about as long as the top part of a grown-up’s thumb. Rulers are marked in inches.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.4 (grade K)
A small length, about as long as the top part of a grown-up’s thumb. Rulers are marked in inches.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.4 (grade K)
industrial regionEnglish
A cluster of related industries, workers, suppliers and transport links in one area, such as Lancashire’s cotton district or Germany’s Ruhr.
Human Geography, Lesson 8.1 (grade 9–12)
A cluster of related industries, workers, suppliers and transport links in one area, such as Lancashire’s cotton district or Germany’s Ruhr.
Human Geography, Lesson 8.1 (grade 9–12)
inland (interior) drainageEnglish
A river system that empties into a lake or sea with no outlet to the ocean, such as the Volga into the Caspian Sea.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
A river system that empties into a lake or sea with no outlet to the ocean, such as the Volga into the Caspian Sea.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
inland seaEnglish
A lake with no outlet to the ocean. Its water leaves only by evaporation, so salts build up.
Grade 7 Geography: Regions of the World, Lesson 3.3 (grade 7)
A lake with no outlet to the ocean. Its water leaves only by evaporation, so salts build up.
Grade 7 Geography: Regions of the World, Lesson 3.3 (grade 7)
inland waterwayEnglish
A river or canal deep enough for barges and boats to carry cargo far from the sea.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8)
A river or canal deep enough for barges and boats to carry cargo far from the sea.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8)
inner or marginal crescentEnglish
The ring of lands around the pivot, “partly continental, partly oceanic”: Europe west of Russia, the Middle East, India and China.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
The ring of lands around the pivot, “partly continental, partly oceanic”: Europe west of Russia, the Middle East, India and China.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
insetEnglish
A small extra map placed inside the border of a larger map.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.2 (grade 5)
A small extra map placed inside the border of a larger map.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.2 (grade 5)
intensive agricultureEnglish
Farming that puts much labor and capital on each acre to get high output per acre (market gardens, dairies).
Human Geography, Lesson 6.2 (grade 9–12)
Farming that puts much labor and capital on each acre to get high output per acre (market gardens, dairies).
Human Geography, Lesson 6.2 (grade 9–12)
intensive subsistence agricultureEnglish
Farming of small plots with much labor per acre to feed a dense population, as in the wet-rice lands of East, South and Southeast Asia.
Human Geography, Lesson 6.4 (grade 9–12)
Farming of small plots with much labor per acre to feed a dense population, as in the wet-rice lands of East, South and Southeast Asia.
Human Geography, Lesson 6.4 (grade 9–12)
interbasin transferEnglish
Moving water by canal, aqueduct or pipeline from one drainage basin to another.
Human Geography, Lesson 9.2 (grade 9–12)
Moving water by canal, aqueduct or pipeline from one drainage basin to another.
Human Geography, Lesson 9.2 (grade 9–12)
interiorEnglish
The inland part of a country, far from the coast.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
The inland part of a country, far from the coast.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
intermodal containerEnglish
A standard steel box that moves between ship, train and truck without its contents being unloaded.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
A standard steel box that moves between ship, train and truck without its contents being unloaded.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
intermodal journeyEnglish
A trip using two or more modes of transport (truck, ship, train, plane) with the cargo staying in the same container or package.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
A trip using two or more modes of transport (truck, ship, train, plane) with the cargo staying in the same container or package.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
internal migrationEnglish
Permanent movement within one country. Interregional migration moves between major regions; intraregional migration moves within a region, as from city to suburb.
Human Geography, Lesson 3.3 (grade 9–12)
Permanent movement within one country. Interregional migration moves between major regions; intraregional migration moves within a region, as from city to suburb.
Human Geography, Lesson 3.3 (grade 9–12)
International Boundary and Water Commission (IBWC)English
The joint U.S.–Mexico body, created in 1889 as the International Boundary Commission, that marks the border and manages the shared rivers.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
The joint U.S.–Mexico body, created in 1889 as the International Boundary Commission, that marks the border and manages the shared rivers.
Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
interval startEnglish
Starting runners one at a time, a minute or more apart, so that each must find the way alone.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
Starting runners one at a time, a minute or more apart, so that each must find the way alone.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
intervening obstacleEnglish
A barrier between origin and destination that makes a move harder: distance, cost, mountains, seas, borders or laws (Everett Lee, 1966).
Human Geography, Lesson 3.1 (grade 9–12)
A barrier between origin and destination that makes a move harder: distance, cost, mountains, seas, borders or laws (Everett Lee, 1966).
Human Geography, Lesson 3.1 (grade 9–12)
intraplate earthquakeEnglish
An earthquake far from any plate edge, inside a plate.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
An earthquake far from any plate edge, inside a plate.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
invasionEnglish
An army entering another country by force to conquer or occupy it.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.4 (grade 8)
An army entering another country by force to conquer or occupy it.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.4 (grade 8)
invasion routeEnglish
A natural path, such as a plain, valley or pass, that lets armies move easily from one land into another.
Grade 7 Geography: Regions of the World, Lesson 1.1 (grade 7)
A natural path, such as a plain, valley or pass, that lets armies move easily from one land into another.
Grade 7 Geography: Regions of the World, Lesson 1.1 (grade 7)
Iron CurtainEnglish
Churchill’s image, in a speech at Fulton, Missouri, on March 5, 1946, for the line dividing Soviet-controlled Eastern Europe from the West.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12)
Churchill’s image, in a speech at Fulton, Missouri, on March 5, 1946, for the line dividing Soviet-controlled Eastern Europe from the West.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12)
iron oreEnglish
Rock with a lot of iron in it. It is melted in furnaces to make iron and steel.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
Rock with a lot of iron in it. It is melted in furnaces to make iron and steel.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
irrigation canalEnglish
A dug channel that leads water from a river to fields, running gently downhill the whole way.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.2 (grade 8)
A dug channel that leads water from a river to fields, running gently downhill the whole way.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.2 (grade 8)
island continentEnglish
A continent with water all the way around it. Australia is the only continent that is also a single country.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.3 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
A continent with water all the way around it. Australia is the only continent that is also a single country.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.3 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
isochroneEnglish
A line on a map joining places that can be reached in the same amount of travel time from a starting point.
Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
A line on a map joining places that can be reached in the same amount of travel time from a starting point.
Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
isodapaneEnglish
A line on a map joining points of equal extra transport cost compared with the least-cost site; used to judge whether cheap labor elsewhere is worth the extra freight.
Human Geography, Lesson 8.2 (grade 9–12)
A line on a map joining points of equal extra transport cost compared with the least-cost site; used to judge whether cheap labor elsewhere is worth the extra freight.
Human Geography, Lesson 8.2 (grade 9–12)
isohyetEnglish
A line on a map joining places that receive the same amount of rain or snow in a year.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
A line on a map joining places that receive the same amount of rain or snow in a year.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
isolation policyEnglish
A government’s choice to keep most foreigners and foreign trade out. Japan held such a policy from the 1630s to the 1850s, and Korea’s Joseon kingdom did much the same.
Grade 7 Geography: Regions of the World, Lesson 6.3 (grade 7)
A government’s choice to keep most foreigners and foreign trade out. Japan held such a policy from the 1630s to the 1850s, and Korea’s Joseon kingdom did much the same.
Grade 7 Geography: Regions of the World, Lesson 6.3 (grade 7)
isothermEnglish
A line on a map joining places with the same average temperature.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
A line on a map joining places with the same average temperature.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.3 (grade 6)
isthmian canalEnglish
A canal cut across an isthmus, a narrow neck of land between two seas, such as the Panama Canal (1914) or the Suez Canal (1869).
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12)
A canal cut across an isthmus, a narrow neck of land between two seas, such as the Panama Canal (1914) or the Suez Canal (1869).
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12)
isthmusEnglish
A narrow strip of land joining two larger land areas and separating two bodies of water, such as the Isthmus of Panama or the Isthmus of Suez.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.1 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7) · +3 more
A narrow strip of land joining two larger land areas and separating two bodies of water, such as the Isthmus of Panama or the Isthmus of Suez.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.1 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7) · +3 more
J
JesuitEnglish
A member of the Society of Jesus, a Catholic order of priests founded in 1540 and known for its schools, scholars and missionaries.
Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7)
A member of the Society of Jesus, a Catholic order of priests founded in 1540 and known for its schools, scholars and missionaries.
Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7)
jet streamEnglish
A narrow band of very strong west-to-east winds high in the atmosphere, near the altitudes where jets cruise; it often blows 100 to 200 mph (160 to 320 km/h).
Technology Overcoming Geography, Lesson 4.4 (grade 9–12) · Technology Overcoming Geography, Lesson 5.4 (grade 9–12)
A narrow band of very strong west-to-east winds high in the atmosphere, near the altitudes where jets cruise; it often blows 100 to 200 mph (160 to 320 km/h).
Technology Overcoming Geography, Lesson 4.4 (grade 9–12) · Technology Overcoming Geography, Lesson 5.4 (grade 9–12)
joint occupationEnglish
The arrangement, agreed by the Convention of 1818 and renewed in 1827, under which citizens of both the United States and Britain could settle and trade in the Oregon Country while neither nation ruled it alone.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
The arrangement, agreed by the Convention of 1818 and renewed in 1827, under which citizens of both the United States and Britain could settle and trade in the Oregon Country while neither nation ruled it alone.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
juteEnglish
A strong plant fiber, grown mostly in Bengal, that was spun and woven into sacks and rope in the mills of Dundee.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5) · Textile Science & Clothing Construction, Lesson 1.5 (grade 9–12)
A strong plant fiber, grown mostly in Bengal, that was spun and woven into sacks and rope in the mills of Dundee.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5) · Textile Science & Clothing Construction, Lesson 1.5 (grade 9–12)
JutlandEnglish
The peninsula of Denmark and northern Germany that separates the North Sea from the Baltic; its northern tip is the Skaw (Skagen).
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
The peninsula of Denmark and northern Germany that separates the North Sea from the Baltic; its northern tip is the Skaw (Skagen).
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
K
K1English
The first copy of Harrison’s H4, made by the London watchmaker Larcum Kendall and finished in 1769. Cook carried it on his second and third voyages.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
The first copy of Harrison’s H4, made by the London watchmaker Larcum Kendall and finished in 1769. Cook carried it on his second and third voyages.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
kamalEnglish
A simple navigation tool of Arab and Indian sailors: a small wooden card on a knotted cord, used to measure the height of the Pole Star above the horizon and so to find latitude.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
A simple navigation tool of Arab and Indian sailors: a small wooden card on a knotted cord, used to measure the height of the Pole Star above the horizon and so to find latitude.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
kamikazeEnglish
Japanese for “divine wind”; the name given to the storms, above all the typhoon of 1281, that wrecked the Mongol fleets.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
Japanese for “divine wind”; the name given to the storms, above all the typhoon of 1281, that wrecked the Mongol fleets.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
kangarooEnglish
An animal from Australia that hops on strong back legs and carries its baby in a pouch.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.3 (grade K)
An animal from Australia that hops on strong back legs and carries its baby in a pouch.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.3 (grade K)
karezEnglish
An underground channel that carries groundwater by gravity from the foot of the mountains to an oasis, dug with a line of vertical shafts (called a qanat in Persia).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12)
An underground channel that carries groundwater by gravity from the foot of the mountains to an oasis, dug with a line of vertical shafts (called a qanat in Persia).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12)
keelboatEnglish
A long, narrow boat that crews pushed upstream with poles or pulled with ropes, very slowly.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
A long, narrow boat that crews pushed upstream with poles or pulled with ropes, very slowly.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
khanEnglish
The title of a Mongol ruler. Kublai Khan was the Great Khan, the highest of all the Mongol rulers.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.3 (grade 3)
The title of a Mongol ruler. Kublai Khan was the Great Khan, the highest of all the Mongol rulers.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.3 (grade 3)
khanateEnglish
A realm ruled by a khan. After 1260 the Mongol Empire divided into four: the Yuan in China, the Chagatai Khanate in Central Asia, the Ilkhanate in Persia and the Golden Horde on the western steppe.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
A realm ruled by a khan. After 1260 the Mongol Empire divided into four: the Yuan in China, the Chagatai Khanate in Central Asia, the Ilkhanate in Persia and the Golden Horde on the western steppe.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
kharif and rabiEnglish
South Asia’s two main crop seasons: kharif crops (such as rice and cotton) are sown with the summer monsoon and harvested in autumn; rabi crops (such as wheat and mustard) are sown in autumn and harvested in spring.
Grade 7 Geography: Regions of the World, Lesson 5.2 (grade 7)
South Asia’s two main crop seasons: kharif crops (such as rice and cotton) are sown with the summer monsoon and harvested in autumn; rabi crops (such as wheat and mustard) are sown in autumn and harvested in spring.
Grade 7 Geography: Regions of the World, Lesson 5.2 (grade 7)
Knights of St JohnEnglish
A Catholic religious and military order (the Knights Hospitaller), founded to care for pilgrims in Jerusalem, which ruled Rhodes and then Malta from 1530 to 1798.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
A Catholic religious and military order (the Knights Hospitaller), founded to care for pilgrims in Jerusalem, which ruled Rhodes and then Malta from 1530 to 1798.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
knot and nautical mileEnglish
A nautical mile is 1.852 km (about 1.15 statute miles), one minute of latitude. A knot is one nautical mile per hour.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
A nautical mile is 1.852 km (about 1.15 statute miles), one minute of latitude. A knot is one nautical mile per hour.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
Köppen systemEnglish
The climate classification of Wladimir Köppen, which names each climate with letters based on monthly temperature and precipitation and the plants that can grow there.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
The climate classification of Wladimir Köppen, which names each climate with letters based on monthly temperature and precipitation and the plants that can grow there.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.4 (grade 6)
Korea StraitEnglish
The sea passage between the southern tip of Korea and the Japanese island of Kyushu, about 200 km (125 miles) wide, divided by the islands of Tsushima and Iki.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
The sea passage between the southern tip of Korea and the Japanese island of Kyushu, about 200 km (125 miles) wide, divided by the islands of Tsushima and Iki.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
krummholzEnglish
A German word meaning “crooked wood”: the low, twisted, wind-pruned trees found just below the tree line.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6)
A German word meaning “crooked wood”: the low, twisted, wind-pruned trees found just below the tree line.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6)
kurganEnglish
A burial mound raised over the grave of a steppe chief or noble; Scythian kurgans have yielded famous gold work.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
A burial mound raised over the grave of a steppe chief or noble; Scythian kurgans have yielded famous gold work.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
KuroshioEnglish
The “Black Current,” a strong, warm current flowing north along the Philippines, Taiwan and Japan, the Pacific counterpart of the Gulf Stream.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 6.3 (grade 7)
The “Black Current,” a strong, warm current flowing north along the Philippines, Taiwan and Japan, the Pacific counterpart of the Gulf Stream.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 6.3 (grade 7)
kurultaiEnglish
A great assembly of Mongol chiefs and nobles that chose a khan and decided on war; Temüjin was proclaimed Chinggis Khan at a kurultai in 1206.
Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
A great assembly of Mongol chiefs and nobles that chose a khan and decided on war; Temüjin was proclaimed Chinggis Khan at a kurultai in 1206.
Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
L
Labrador CurrentEnglish
A cold current that flows south from the Arctic along the coasts of Labrador and Newfoundland, carrying sea ice and icebergs.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
A cold current that flows south from the Arctic along the coasts of Labrador and Newfoundland, carrying sea ice and icebergs.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
lagoonEnglish
A shallow body of salt water cut off from the open sea by low strips of land or sandbars.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.1 (grade 3) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.1 (grade 8)
A shallow body of salt water cut off from the open sea by low strips of land or sandbars.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.1 (grade 3) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.1 (grade 8)
lakeEnglish
A big pool of water that rests in a low place, with land all around it.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.2 (grade K)
A big pool of water that rests in a low place, with land all around it.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.2 (grade K)
lake bedEnglish
The bottom of a lake; the ground left behind when a lake dries up or is drained.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.4 (grade 3)
The bottom of a lake; the ground left behind when a lake dries up or is drained.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.4 (grade 3)
land bridgeEnglish
A narrow strip of land that connects two larger land masses and funnels travel between them. The lands at the eastern end of the Mediterranean link Africa and Asia.
Grade 7 Geography: Regions of the World, Lesson 3.3 (grade 7)
A narrow strip of land that connects two larger land masses and funnels travel between them. The lands at the eastern end of the Mediterranean link Africa and Asia.
Grade 7 Geography: Regions of the World, Lesson 3.3 (grade 7)
land grantEnglish
Public land given to a railroad company to help pay for building. The transcontinental grants were alternate square-mile sections on each side of the track, making a checkerboard of railroad and government land.
Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12) · Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
Public land given to a railroad company to help pay for building. The transcontinental grants were alternate square-mile sections on each side of the track, making a checkerboard of railroad and government land.
Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12) · Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
Land Ordinance of 1785English
A law passed by Congress on May 20, 1785, that ordered the western lands to be surveyed into squares before they were sold.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.4 (grade 4)
A law passed by Congress on May 20, 1785, that ordered the western lands to be surveyed into squares before they were sold.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.4 (grade 4)
land powerEnglish
Strength that rests on armies, a secure home territory and the ability to hold and take ground.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12)
Strength that rests on armies, a secure home territory and the ability to hold and take ground.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12)
land reclamationEnglish
Making new land by filling in shallow sea, swamp or river edges with sand, soil or rock.
Grade 7 Geography: Regions of the World, Lesson 7.2 (grade 7)
Making new land by filling in shallow sea, swamp or river edges with sand, soil or rock.
Grade 7 Geography: Regions of the World, Lesson 7.2 (grade 7)
land useEnglish
The human purpose to which an area of land is put: farming, forestry, housing, industry, transportation, recreation or preservation.
Human Geography, Lesson 9.3 (grade 9–12)
The human purpose to which an area of land is put: farming, forestry, housing, industry, transportation, recreation or preservation.
Human Geography, Lesson 9.3 (grade 9–12)
landed costEnglish
The full cost of a product once it arrives in the buyer’s country: the factory price plus freight, insurance, duties and handling.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
The full cost of a product once it arrives in the buyer’s country: the factory price plus freight, insurance, duties and handling.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
landingEnglish
A place on the riverbank where boats tie up to load and unload goods and passengers.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
A place on the riverbank where boats tie up to load and unload goods and passengers.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
landing stationEnglish
The building on shore where an undersea cable comes out of the sea and connects to the networks on land.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
The building on shore where an undersea cable comes out of the sea and connects to the networks on land.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
landlockedEnglish
Having no coastline on the open ocean. Kazakhstan is the largest landlocked country in the world.
Grade 7 Geography: Regions of the World, Lesson 2.4 (grade 7) · Grade 7 Geography: Regions of the World, Lesson 4.4 (grade 7)
Having no coastline on the open ocean. Kazakhstan is the largest landlocked country in the world.
Grade 7 Geography: Regions of the World, Lesson 2.4 (grade 7) · Grade 7 Geography: Regions of the World, Lesson 4.4 (grade 7)
language branchEnglish
A large division within a family whose languages share a closer common ancestor (for example, the Germanic branch of Indo-European, which includes English and German).
Human Geography, Lesson 4.1 (grade 9–12)
A large division within a family whose languages share a closer common ancestor (for example, the Germanic branch of Indo-European, which includes English and German).
Human Geography, Lesson 4.1 (grade 9–12)
language familyEnglish
A group of languages that grew from a common ancestor. North India speaks mostly Indo-Aryan languages (such as Hindi and Bengali); the south speaks mostly Dravidian languages (such as Tamil and Telugu).
Grade 7 Geography: Regions of the World, Lesson 5.4 (grade 7) · Human Geography, Lesson 4.1 (grade 9–12)
A group of languages that grew from a common ancestor. North India speaks mostly Indo-Aryan languages (such as Hindi and Bengali); the south speaks mostly Dravidian languages (such as Tamil and Telugu).
Grade 7 Geography: Regions of the World, Lesson 5.4 (grade 7) · Human Geography, Lesson 4.1 (grade 9–12)
language isolateEnglish
A language with no proven relatives in any known family, such as Basque in the western Pyrenees.
Human Geography, Lesson 4.1 (grade 9–12)
A language with no proven relatives in any known family, such as Basque in the western Pyrenees.
Human Geography, Lesson 4.1 (grade 9–12)
large-scale and small-scale mapEnglish
A large-scale map (such as 1:24,000) shows a small area in great detail; a small-scale map (such as 1:50,000,000) shows a large area with little detail. The larger the fraction, the larger the scale.
Human Geography, Lesson 1.1 (grade 9–12)
A large-scale map (such as 1:24,000) shows a small area in great detail; a small-scale map (such as 1:50,000,000) shows a large area with little detail. The larger the fraction, the larger the scale.
Human Geography, Lesson 1.1 (grade 9–12)
lateen sailEnglish
A triangular sail hung from a long yard set at a slant to the mast. It can sail closer to the wind than a square sail, but the yard must be swung around the mast to change tack.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.1 (grade 5) · +1 more
A triangular sail hung from a long yard set at a slant to the mast. It can sail closer to the wind than a square sail, but the yard must be swung around the mast to change tack.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.2 (grade 9–12) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.1 (grade 5) · +1 more
latencyEnglish
The time a signal takes to travel from sender to receiver. It is limited by distance and the speed of light in the medium.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
The time a signal takes to travel from sender to receiver. It is limited by distance and the speed of light in the medium.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
law of sinesEnglish
In any triangle, each side divided by the sine of the opposite angle gives the same number: a/sin A = b/sin B = c/sin C.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12) · Trigonometry, Lesson 7.2 (grade 11–12)
In any triangle, each side divided by the sine of the opposite angle gives the same number: a/sin A = b/sin B = c/sin C.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12) · Trigonometry, Lesson 7.2 (grade 11–12)
leagueEnglish
An old unit of distance, roughly 3 to 4 miles (about 5 to 6.5 km), whose exact length varied from country to country and from author to author.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
An old unit of distance, roughly 3 to 4 miles (about 5 to 6.5 km), whose exact length varied from country to country and from author to author.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
least-cost locationEnglish
Alfred Weber’s idea (1909) that a factory will tend to locate where the total cost of moving raw materials in and products out is lowest.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
Alfred Weber’s idea (1909) that a factory will tend to locate where the total cost of moving raw materials in and products out is lowest.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
least-cost theoryEnglish
Alfred Weber’s model (1909): a factory will locate where the total cost of transport, labor and agglomeration is lowest, with transport cost usually the strongest pull.
Human Geography, Lesson 8.2 (grade 9–12)
Alfred Weber’s model (1909): a factory will locate where the total cost of transport, labor and agglomeration is lowest, with transport cost usually the strongest pull.
Human Geography, Lesson 8.2 (grade 9–12)
LebensraumEnglish
German for “living space.” Ratzel used it for the territory a people or species needs; the Nazi regime used it to mean land in the East to be seized from Poles, Russians, Ukrainians and others.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
German for “living space.” Ratzel used it for the territory a people or species needs; the Nazi regime used it to mean land in the East to be seized from Poles, Russians, Ukrainians and others.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
leewardEnglish
The side of a mountain range sheltered from the wind, where air sinks, warms and dries.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6)
The side of a mountain range sheltered from the wind, where air sinks, warms and dries.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6)
leewayEnglish
The sideways drift of a ship pushed by the wind, so that it does not travel exactly where it is pointed.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
The sideways drift of a ship pushed by the wind, so that it does not travel exactly where it is pointed.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
left and rightEnglish
The two sides of your body. Your right hand and your left hand point to your right side and your left side.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.3 (grade K)
The two sides of your body. Your right hand and your left hand point to your right side and your left side.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.3 (grade K)
left bank and right bankEnglish
The banks of a river named as you face downstream. The Rhine flows north, so its left bank is the west bank.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
The banks of a river named as you face downstream. The Rhine flows north, so its left bank is the west bank.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
LenalandEnglish
Mackinder’s 1943 name for the thinly peopled lands of eastern Siberia east of the Yenisei, which he set apart from the Heartland proper.
Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12)
Mackinder’s 1943 name for the thinly peopled lands of eastern Siberia east of the Yenisei, which he set apart from the Heartland proper.
Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12)
license plateEnglish
The metal sign on the front or back of a car. It shows the car’s number and the state where the car belongs.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.4 (grade 2)
The metal sign on the front or back of a car. It shows the car’s number and the state where the car belongs.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.4 (grade 2)
lighterEnglish
A flat-bottomed barge used to carry cargo between ships and the shore.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
A flat-bottomed barge used to carry cargo between ships and the shore.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
lignum vitaeEnglish
A very hard, naturally oily tropical wood. Harrison used it in his wooden clocks because it needs no oil.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.2 (grade 5)
A very hard, naturally oily tropical wood. Harrison used it in his wooden clocks because it needs no oil.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.2 (grade 5)
limesEnglish
Latin for a path or boundary; historians use it for the fortified frontiers of the Roman Empire, with their roads, forts, watchtowers and walls.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12)
Latin for a path or boundary; historians use it for the fortified frontiers of the Roman Empire, with their roads, forts, watchtowers and walls.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12)
limited commandEnglish
Julian Corbett’s idea that command of the sea is usually partial and local, in place and time, and that navies matter chiefly by what they make possible on land.
Geopolitics: The Great Ideas, Lesson 2.5 (grade 9–12)
Julian Corbett’s idea that command of the sea is usually partial and local, in place and time, and that navies matter chiefly by what they make possible on land.
Geopolitics: The Great Ideas, Lesson 2.5 (grade 9–12)
limits of the argumentEnglish
An honest statement of what the paper cannot prove, what evidence is missing, and what could change the conclusion.
Geopolitics: The Great Ideas, Lesson 5.4 (grade 9–12)
An honest statement of what the paper cannot prove, what evidence is missing, and what could change the conclusion.
Geopolitics: The Great Ideas, Lesson 5.4 (grade 9–12)
Line of Actual Control (LAC)English
The line separating areas actually held by India and China, which in many places differs from what each side claims.
Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12)
The line separating areas actually held by India and China, which in many places differs from what each side claims.
Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12)
line of demarcationEnglish
A boundary line agreed on to separate the claims of two parties. The term is used for both the papal line of 1493 and the treaty line of 1494.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
A boundary line agreed on to separate the claims of two parties. The term is used for both the papal line of 1493 and the treaty line of 1494.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
line of supply (line of communication)English
The road and depots that connect an army to its sources of food, ammunition, fodder and replacements. The longer it grows, the harder it is to keep full and safe.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
The road and depots that connect an army to its sources of food, ammunition, fodder and replacements. The longer it grows, the harder it is to keep full and safe.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
lingua francaEnglish
A language used for communication between people whose native languages differ (Latin in medieval Europe, Swahili in East Africa, English in aviation and science today).
Human Geography, Lesson 4.1 (grade 9–12)
A language used for communication between people whose native languages differ (Latin in medieval Europe, Swahili in East Africa, English in aviation and science today).
Human Geography, Lesson 4.1 (grade 9–12)
liquefactionEnglish
When strong shaking makes loose, wet, sandy ground act like a thick liquid, so buildings tilt or sink.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 3.4 (grade 6)
When strong shaking makes loose, wet, sandy ground act like a thick liquid, so buildings tilt or sink.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 3.4 (grade 6)
liquefied natural gas (LNG)English
Natural gas cooled to about −162 °C (−260 °F) so that it becomes a liquid taking up about 1/600 of its gas volume, and can be carried in special tankers.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
Natural gas cooled to about −162 °C (−260 °F) so that it becomes a liquid taking up about 1/600 of its gas volume, and can be carried in special tankers.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
llamaEnglish
A woolly animal from the mountains of South America that helps people carry loads.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.3 (grade K)
A woolly animal from the mountains of South America that helps people carry loads.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.3 (grade K)
LNGEnglish
Liquefied natural gas: gas chilled to about −162 °C (−260 °F) until it becomes a liquid taking up about 1/600 of its volume as a gas, so it can be shipped by sea.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.4 (grade 9–12)
Liquefied natural gas: gas chilled to about −162 °C (−260 °F) until it becomes a liquid taking up about 1/600 of its volume as a gas, so it can be shipped by sea.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.4 (grade 9–12)
local apparent timeEnglish
Time told by the sun at a particular place: it is noon when the sun crosses the local meridian and stands highest in the sky.
Technology Overcoming Geography, Lesson 1.3 (grade 9–12)
Time told by the sun at a particular place: it is noon when the sun crosses the local meridian and stands highest in the sky.
Technology Overcoming Geography, Lesson 1.3 (grade 9–12)
local noonEnglish
The moment the sun is highest in the sky at a place. In most of the United States the sun is then due south and shadows are shortest and point due north.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.3 (grade 5)
The moment the sun is highest in the sky at a place. In most of the United States the sun is then due south and shadows are shortest and point due north.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.3 (grade 5)
local timeEnglish
Time kept by the sun at one place, so that noon comes when the sun is highest there.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.3 (grade 5)
Time kept by the sun at one place, so that noon comes when the sun is highest there.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.3 (grade 5)
location quotientEnglish
A ratio comparing a place’s share of some activity to the nation’s share: LQ = (local share) ÷ (national share). Above 1 means the place specializes in it.
Human Geography, Lesson 10.2 (grade 9–12)
A ratio comparing a place’s share of some activity to the nation’s share: LQ = (local share) ÷ (national share). Above 1 means the place specializes in it.
Human Geography, Lesson 10.2 (grade 9–12)
location quotient (LQ)English
A ratio that compares a local share with a larger share: (local share of an industry or group) ÷ (national share). An LQ above 1 means the place is more concentrated in it than the nation.
Human Geography, Lesson 1.3 (grade 9–12) · Human Geography, Lesson 6.4 (grade 9–12) · Human Geography, Lesson 8.1 (grade 9–12)
A ratio that compares a local share with a larger share: (local share of an industry or group) ÷ (national share). An LQ above 1 means the place is more concentrated in it than the nation.
Human Geography, Lesson 1.3 (grade 9–12) · Human Geography, Lesson 6.4 (grade 9–12) · Human Geography, Lesson 8.1 (grade 9–12)
locational rent (bid rent)English
The profit a unit of land can earn for a given use at a given distance from market; the most a farmer could pay for that land and still break even. R = Y(p − c) − Yfd.
Human Geography, Lesson 6.2 (grade 9–12)
The profit a unit of land can earn for a given use at a given distance from market; the most a farmer could pay for that land and still break even. R = Y(p − c) − Yfd.
Human Geography, Lesson 6.2 (grade 9–12)
locational triangleEnglish
Weber’s diagram with two raw-material sources and a market at its corners; the least-cost factory site lies at a corner or inside the triangle, pulled toward whichever input or output weighs most.
Human Geography, Lesson 8.2 (grade 9–12)
Weber’s diagram with two raw-material sources and a market at its corners; the least-cost factory site lies at a corner or inside the triangle, pulled toward whichever input or output weighs most.
Human Geography, Lesson 8.2 (grade 9–12)
lock canalEnglish
A canal that uses locks to lift ships up over high ground and lower them down again on the other side.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.3 (grade 8)
A canal that uses locks to lift ships up over high ground and lower them down again on the other side.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.3 (grade 8)
lock chamberEnglish
The long box of water inside a lock where the boat waits while the water rises or falls.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.2 (grade 4)
The long box of water inside a lock where the boat waits while the water rises or falls.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.2 (grade 4)
lockageEnglish
One complete passage of a ship (or group of ships) through a lock chamber, using one chamber-full of water.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
One complete passage of a ship (or group of ships) through a lock chamber, using one chamber-full of water.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
log lineEnglish
A line knotted at regular spaces and tied to a wooden float (the chip log), paid out over the stern for a set time measured by a sandglass; the number of knots that run out gives the ship’s speed in knots.
Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
A line knotted at regular spaces and tied to a wooden float (the chip log), paid out over the stern for a set time measured by a sandglass; the number of knots that run out gives the ship’s speed in knots.
Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
Long TelegramEnglish
Kennan’s message of February 22, 1946, sent from the U.S. embassy in Moscow in five parts, explaining the sources of Soviet behavior and how the United States should respond.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
Kennan’s message of February 22, 1946, sent from the U.S. embassy in Moscow in five parts, explaining the sources of Soviet behavior and how the United States should respond.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
Long WallsEnglish
The walls, built about 461–456 B.C., that joined Athens to its harbor at Piraeus, so the city could be supplied by sea during a siege.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8)
The walls, built about 461–456 B.C., that joined Athens to its harbor at Piraeus, so the city could be supplied by sea during a siege.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8)
longhouseEnglish
A long house made of bent young trees covered with sheets of bark, where several families lived together.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.1 (grade 2)
A long house made of bent young trees covered with sheets of bark, where several families lived together.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.1 (grade 2)
longshoremanEnglish
A dock worker who loads and unloads ships (also called a stevedore or docker).
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.3 (grade 8) · Technology Overcoming Geography, Lesson 4.5 (grade 9–12)
A dock worker who loads and unloads ships (also called a stevedore or docker).
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.3 (grade 8) · Technology Overcoming Geography, Lesson 4.5 (grade 9–12)
Lotharingia (the Middle Kingdom)English
The long strip of land between West and East Francia given to Lothair I in 843, from the North Sea toward Italy, including the Rhine lands.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
The long strip of land between West and East Francia given to Lothair I in 843, from the North Sea toward Italy, including the Rhine lands.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
low Earth orbitEnglish
An orbit roughly 160 to 2,000 km (100 to 1,200 miles) above the earth, where a satellite circles the globe in about 90 minutes to two hours.
Technology Overcoming Geography, Lesson 5.1 (grade 9–12)
An orbit roughly 160 to 2,000 km (100 to 1,200 miles) above the earth, where a satellite circles the globe in about 90 minutes to two hours.
Technology Overcoming Geography, Lesson 5.1 (grade 9–12)
lowest bridging pointEnglish
The point farthest downstream (nearest the sea) where a river could be bridged; often also the highest point that seagoing ships could reach.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)
The point farthest downstream (nearest the sea) where a river could be bridged; often also the highest point that seagoing ships could reach.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)
lunar distanceEnglish
The angle between the moon and a star or the sun, measured with an instrument and used with printed tables to find Greenwich time at sea.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.2 (grade 5) · Technology Overcoming Geography, Lesson 1.3 (grade 9–12)
The angle between the moon and a star or the sun, measured with an instrument and used with printed tables to find Greenwich time at sea.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.2 (grade 5) · Technology Overcoming Geography, Lesson 1.3 (grade 9–12)
M
magnetic variation (declination)English
The angle between true north (toward the North Pole) and magnetic north (where a compass needle points). It changes from place to place and slowly over the years.
Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
The angle between true north (toward the North Pole) and magnetic north (where a compass needle points). It changes from place to place and slowly over the years.
Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
mail carrierEnglish
The helper who brings letters and packages to our homes.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 6.2 (grade K)
The helper who brings letters and packages to our homes.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 6.2 (grade K)
main stemEnglish
The principal river of a river system, which receives the tributaries.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.2 (grade 8)
The principal river of a river system, which receives the tributaries.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.2 (grade 8)
MakahikiEnglish
The Hawaiian season of harvest and peace, held in honor of the god Lono, when war was set aside and gifts were brought to the chiefs.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
The Hawaiian season of harvest and peace, held in honor of the god Lono, when war was set aside and gifts were brought to the chiefs.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
malariaEnglish
A disease that causes fever and chills, caused by a tiny parasite carried by Anopheles mosquitoes.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.3 (grade 8) · Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
A disease that causes fever and chills, caused by a tiny parasite carried by Anopheles mosquitoes.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.3 (grade 8) · Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
mandateEnglish
A territory taken from Germany or the Ottoman Empire after World War I and placed by the League of Nations under the administration of a victorious power, which was to prepare it for self-government.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
A territory taken from Germany or the Ottoman Empire after World War I and placed by the League of Nations under the administration of a victorious power, which was to prepare it for self-government.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
mangroveEnglish
A tree that grows in salty or muddy water along tropical coasts and river mouths, standing on tangled roots.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5)
A tree that grows in salty or muddy water along tropical coasts and river mouths, standing on tangled roots.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5)
manifest destinyEnglish
The belief, popular in the United States in the 1840s, that the nation was meant by Providence to spread across North America. The phrase was coined by the editor John L. O’Sullivan in 1845.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
The belief, popular in the United States in the 1840s, that the nation was meant by Providence to spread across North America. The phrase was coined by the editor John L. O’Sullivan in 1845.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
mansio and mutatioEnglish
Stations of the cursus publicus. A mutatio was a changing station for fresh animals; a mansio was a larger stopping place with lodging for the night.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
Stations of the cursus publicus. A mutatio was a changing station for fresh animals; a mansio was a larger stopping place with lodging for the night.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
manufacturingEnglish
Making goods in large amounts, usually in factories.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4)
Making goods in large amounts, usually in factories.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4)
map indexEnglish
An alphabetical list of the places on a map, each with its grid reference, so you can find it quickly.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.2 (grade 4)
An alphabetical list of the places on a map, each with its grid reference, so you can find it quickly.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.2 (grade 4)
map keyEnglish
A box on a map that shows each symbol and tells what it means. It is also called a legend.
Grade 1 Geography: Maps and Journeys, Lesson 1.3 (grade 1) · Grade 1 Geography: Maps and Journeys, Lesson 9.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.2 (grade 2) · +3 more
A box on a map that shows each symbol and tells what it means. It is also called a legend.
Grade 1 Geography: Maps and Journeys, Lesson 1.3 (grade 1) · Grade 1 Geography: Maps and Journeys, Lesson 9.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.2 (grade 2) · +3 more
map key (legend)English
The table on a map that explains its colors, lines and symbols. On historical maps colors often stand for rulers or dynasties, not modern nations.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12)
The table on a map that explains its colors, lines and symbols. On historical maps colors often stand for rulers or dynasties, not modern nations.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12)
map sentenceEnglish
A single sentence that fixes a geographic idea in the listener’s mind by naming real places, as in Churchill’s “From Stettin in the Baltic to Trieste in the Adriatic.”
Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12)
A single sentence that fixes a geographic idea in the listener’s mind by naming real places, as in Churchill’s “From Stettin in the Baltic to Trieste in the Adriatic.”
Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12)
map setEnglish
A group of maps of the same region at matching scales, each showing one kind of fact (physical, routes, history, views), meant to be read together.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
A group of maps of the same region at matching scales, each showing one kind of fact (physical, routes, history, views), meant to be read together.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
marchEnglish
In medieval Europe, a borderland province organized for defense under a military governor, a margrave (“march count”) or marquis, such as the Spanish March or the March of Brandenburg.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12)
In medieval Europe, a borderland province organized for defense under a military governor, a margrave (“march count”) or marquis, such as the Spanish March or the March of Brandenburg.
Geography and History: Why Borders Fall Where They Do, Lesson 1.4 (grade 9–12)
mare nostrumEnglish
Latin for “our sea,” the Romans’ name for the Mediterranean once they ruled every shore of it.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
Latin for “our sea,” the Romans’ name for the Mediterranean once they ruled every shore of it.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
margin of cultivationEnglish
The distance from market at which a crop’s locational rent falls to zero; beyond it, growing that crop for market loses money.
Human Geography, Lesson 6.2 (grade 9–12)
The distance from market at which a crop’s locational rent falls to zero; beyond it, growing that crop for market loses money.
Human Geography, Lesson 6.2 (grade 9–12)
marginal seasEnglish
The seas that wash the rimland and link it to the ocean: the Mediterranean, the Red Sea, the Persian Gulf, the Bay of Bengal, the South China Sea and the Sea of Japan, among others.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
The seas that wash the rimland and link it to the ocean: the Mediterranean, the Red Sea, the Persian Gulf, the Bay of Bengal, the South China Sea and the Sea of Japan, among others.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
Mariana TrenchEnglish
The deepest trench on earth, in the western Pacific Ocean near the island of Guam.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.4 (grade 3)
The deepest trench on earth, in the western Pacific Ocean near the island of Guam.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.4 (grade 3)
mariner’s astrolabeEnglish
A heavy brass ring, open so the wind can blow through it, hung from a thumb ring, with a turning sighting arm and a scale of degrees. Sailors used it to measure the height of the sun or a star.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.2 (grade 5) · Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
A heavy brass ring, open so the wind can blow through it, hung from a thumb ring, with a turning sighting arm and a scale of degrees. Sailors used it to measure the height of the sun or a star.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.2 (grade 5) · Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
maritime climateEnglish
The mild climate of places where winds blow in from the sea: cool summers, mild winters and rain in all seasons.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
The mild climate of places where winds blow in from the sea: cool summers, mild winters and rain in all seasons.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
market area (hinterland)English
The area surrounding a central place from which people come to buy its goods and services; in Christaller’s model, a hexagon.
Human Geography, Lesson 7.2 (grade 9–12)
The area surrounding a central place from which people come to buy its goods and services; in Christaller’s model, a hexagon.
Human Geography, Lesson 7.2 (grade 9–12)
matchEnglish
To put together two things that go with each other.
Grade 1 Geography: Maps and Journeys, Lesson 9.2 (grade 1)
To put together two things that go with each other.
Grade 1 Geography: Maps and Journeys, Lesson 9.2 (grade 1)
material indexEnglish
The weight of localized raw materials divided by the weight of the finished product. Above 1 means weight-losing (locate near materials); below 1 means weight-gaining (locate near market).
Human Geography, Lesson 8.2 (grade 9–12)
The weight of localized raw materials divided by the weight of the finished product. Above 1 means weight-losing (locate near materials); below 1 means weight-gaining (locate near market).
Human Geography, Lesson 8.2 (grade 9–12)
McMahon LineEnglish
The boundary between British India and Tibet in the eastern Himalaya agreed by British and Tibetan representatives in 1914. India treats it as the border; China has never accepted it.
Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12)
The boundary between British India and Tibet in the eastern Himalaya agreed by British and Tibetan representatives in 1914. India treats it as the border; China has never accepted it.
Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12)
mean center of populationEnglish
The point on which a flat map of the country would balance if every person had the same weight. The Census Bureau computes it every ten years.
Human Geography, Lesson 3.3 (grade 9–12)
The point on which a flat map of the country would balance if every person had the same weight. The Census Bureau computes it every ten years.
Human Geography, Lesson 3.3 (grade 9–12)
meanderEnglish
A wide, looping bend in a river flowing across gentle, flat land.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6) · Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
A wide, looping bend in a river flowing across gentle, flat land.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6) · Geography and History: Why Borders Fall Where They Do, Lesson 2.3 (grade 9–12)
mechanical weatheringEnglish
Breaking rock into smaller pieces without changing the minerals it is made of (also called physical weathering).
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.1 (grade 6)
Breaking rock into smaller pieces without changing the minerals it is made of (also called physical weathering).
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.1 (grade 6)
median lineEnglish
A border drawn down the exact middle of a river, halfway between the two banks.
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
A border drawn down the exact middle of a river, halfway between the two banks.
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
mediationEnglish
Help from a neutral party who brings two sides to agree, without imposing a ruling. Pope John Paul II mediated the Beagle Channel dispute.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
Help from a neutral party who brings two sides to agree, without imposing a ruling. Pope John Paul II mediated the Beagle Channel dispute.
Geography and History: Why Borders Fall Where They Do, Lesson 3.4 (grade 9–12)
Mediterranean climateEnglish
A climate of hot, dry summers and mild, rainy winters (Köppen “Cs”), found around the Mediterranean Sea and in places such as California and central Chile.
Grade 7 Geography: Regions of the World, Lesson 1.2 (grade 7)
A climate of hot, dry summers and mild, rainy winters (Köppen “Cs”), found around the Mediterranean Sea and in places such as California and central Chile.
Grade 7 Geography: Regions of the World, Lesson 1.2 (grade 7)
Mediterranean triadEnglish
The three crops that fed the ancient Mediterranean world: wheat, olives and grapes.
Grade 7 Geography: Regions of the World, Lesson 1.2 (grade 7)
The three crops that fed the ancient Mediterranean world: wheat, olives and grapes.
Grade 7 Geography: Regions of the World, Lesson 1.2 (grade 7)
megalopolisEnglish
Geographer Jean Gottmann’s term (1961) for a chain of metropolitan areas grown together, especially the corridor from Boston to Washington, D.C.
Human Geography, Lesson 7.4 (grade 9–12)
Geographer Jean Gottmann’s term (1961) for a chain of metropolitan areas grown together, especially the corridor from Boston to Washington, D.C.
Human Geography, Lesson 7.4 (grade 9–12)
memory mapEnglish
A map you draw without looking at any other map, to show what you know by heart.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.3 (grade 3)
A map you draw without looking at any other map, to show what you know by heart.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.3 (grade 3)
Mercator projectionEnglish
Mercator’s 1569 way of drawing the world, with straight, parallel lines of longitude and latitude lines spread farther apart toward the poles.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.3 (grade 5)
Mercator’s 1569 way of drawing the world, with straight, parallel lines of longitude and latitude lines spread farther apart toward the poles.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.3 (grade 5)
mesaEnglish
A small plateau with steep cliff sides. Mesa is the Spanish word for “table.”
Grade 1 Geography: Maps and Journeys, Lesson 3.1 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.4 (grade 2) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2) · +1 more
A small plateau with steep cliff sides. Mesa is the Spanish word for “table.”
Grade 1 Geography: Maps and Journeys, Lesson 3.1 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.4 (grade 2) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2) · +1 more
Mexican PlateauEnglish
The high, wide tableland in the middle of Mexico between the Sierra Madre Occidental and the Sierra Madre Oriental. Its southern end, around Mexico City, is more than 2,000 m (6,500 ft) high.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
The high, wide tableland in the middle of Mexico between the Sierra Madre Occidental and the Sierra Madre Oriental. Its southern end, around Mexico City, is more than 2,000 m (6,500 ft) high.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
MexicoEnglish
The country to the south of the United States. Its capital is Mexico City.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1)
The country to the south of the United States. Its capital is Mexico City.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1)
miasmaEnglish
The old theory that diseases came from “bad air” rising from swamps and rotting matter; it led doctors to fight the wrong enemy.
Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
The old theory that diseases came from “bad air” rising from swamps and rotting matter; it led doctors to fight the wrong enemy.
Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
Mid-AtlanticEnglish
The states in the middle of the East Coast: New York, New Jersey, Pennsylvania, Delaware and Maryland.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.2 (grade 4)
The states in the middle of the East Coast: New York, New Jersey, Pennsylvania, Delaware and Maryland.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.2 (grade 4)
Mid-Atlantic RidgeEnglish
A long chain of mountains on the floor of the Atlantic that runs down the middle of the ocean from north to south.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3)
A long chain of mountains on the floor of the Atlantic that runs down the middle of the ocean from north to south.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3)
Midland OceanEnglish
Mackinder’s 1943 name for the North Atlantic and its connected seas, the basin around which Britain, France, the United States and Canada could balance the Heartland power.
Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12)
Mackinder’s 1943 name for the North Atlantic and its connected seas, the basin around which Britain, France, the United States and Canada could balance the Heartland power.
Geopolitics: The Great Ideas, Lesson 3.5 (grade 9–12)
midnight sunEnglish
The summer days north of the Arctic Circle (or south of the Antarctic Circle) when the sun does not set.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
The summer days north of the Arctic Circle (or south of the Antarctic Circle) when the sun does not set.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6)
mid-ocean ridgeEnglish
A long underwater mountain range where two plates spread apart and new ocean crust forms. The Mid-Atlantic Ridge runs about 16,000 km (10,000 mi) down the Atlantic.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6)
A long underwater mountain range where two plates spread apart and new ocean crust forms. The Mid-Atlantic Ridge runs about 16,000 km (10,000 mi) down the Atlantic.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6)
milestone (miliarium)English
A stone column set beside a Roman road at each Roman mile, often carved with the distance and the name of the official or emperor who built or repaired the road.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
A stone column set beside a Roman road at each Roman mile, often carved with the distance and the name of the official or emperor who built or repaired the road.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
Military Demarcation Line (MDL)English
The line where the armies stood when the Korean War armistice was signed on July 27, 1953. It is the working border between North and South Korea.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
The line where the armies stood when the Korean War armistice was signed on July 27, 1953. It is the working border between North and South Korea.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
Military FrontierEnglish
The Habsburg border zone facing the Ottoman Empire, settled by soldier-farmers who held land in return for military service.
Geography and History: Why Borders Fall Where They Do, Lesson 2.2 (grade 9–12)
The Habsburg border zone facing the Ottoman Empire, settled by soldier-farmers who held land in return for military service.
Geography and History: Why Borders Fall Where They Do, Lesson 2.2 (grade 9–12)
milkshedEnglish
The area around a city from which fresh milk can be delivered before it spoils; it widens as transport and refrigeration improve.
Human Geography, Lesson 6.2 (grade 9–12)
The area around a city from which fresh milk can be delivered before it spoils; it widens as transport and refrigeration improve.
Human Geography, Lesson 6.2 (grade 9–12)
mill townEnglish
A town that grew up around mills, usually beside a waterfall or rapids on a fast river.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.1 (grade 4)
A town that grew up around mills, usually beside a waterfall or rapids on a fast river.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.1 (grade 4)
Ming dynastyEnglish
The Chinese dynasty that ruled from 1368 to 1644, founded after the fall of the Mongol Yuan dynasty.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
The Chinese dynasty that ruled from 1368 to 1644, founded after the fall of the Mongol Yuan dynasty.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
minute (of arc)English
One sixtieth of a degree. 41°30′ means 41 and a half degrees. The mark ′ stands for minutes.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.1 (grade 5)
One sixtieth of a degree. 41°30′ means 41 and a half degrees. The mark ′ stands for minutes.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.1 (grade 5)
misunderstandingEnglish
When two people or peoples take each other’s words or actions to mean something they do not mean.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
When two people or peoples take each other’s words or actions to mean something they do not mean.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
miter gateEnglish
A pair of gate leaves that close at an angle, pointing upstream, so that the higher water presses them tightly shut.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
A pair of gate leaves that close at an angle, pointing upstream, so that the higher water presses them tightly shut.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
mitigationEnglish
Actions taken before a hazard strikes to reduce the harm it can do, such as building codes, seawalls, levees and floodplain zoning.
Human Geography, Lesson 9.4 (grade 9–12)
Actions taken before a hazard strikes to reduce the harm it can do, such as building codes, seawalls, levees and floodplain zoning.
Human Geography, Lesson 9.4 (grade 9–12)
moatEnglish
A ditch of water around a castle; used here for a stretch of sea that protects an island country from invasion.
Geography and History: Why Borders Fall Where They Do, Lesson 5.1 (grade 9–12)
A ditch of water around a castle; used here for a stretch of sea that protects an island country from invasion.
Geography and History: Why Borders Fall Where They Do, Lesson 5.1 (grade 9–12)
modifiable areal unit problem (MAUP)English
The fact that the patterns and results of an analysis can change when the same data are grouped into different-sized or differently drawn areas.
Human Geography, Lesson 1.4 (grade 9–12)
The fact that the patterns and results of an analysis can change when the same data are grouped into different-sized or differently drawn areas.
Human Geography, Lesson 1.4 (grade 9–12)
Moluccas (Maluku)English
The island group of eastern Indonesia between Sulawesi and New Guinea, called the Spice Islands. Cloves came from five small islands in the north (Ternate, Tidore, Moti, Makian and Bacan).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
The island group of eastern Indonesia between Sulawesi and New Guinea, called the Spice Islands. Cloves came from five small islands in the north (Ternate, Tidore, Moti, Makian and Bacan).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
MongolsEnglish
Horse-riding people from the grasslands north of China who built the largest land empire the world had ever seen.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.3 (grade 3)
Horse-riding people from the grasslands north of China who built the largest land empire the world had ever seen.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.3 (grade 3)
Monroe DoctrineEnglish
The policy announced in President Monroe’s annual message of December 2, 1823: the Americas were closed to new European colonies, and European interference in the hemisphere would be treated as a danger to the United States.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.5 (grade 9–12)
The policy announced in President Monroe’s annual message of December 2, 1823: the Americas were closed to new European colonies, and European interference in the hemisphere would be treated as a danger to the United States.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.5 (grade 9–12)
monsoonEnglish
A seasonal reversal of the prevailing wind over a large region. The word comes from the Arabic mawsim, “season,” through the Portuguese monção. In the northern Indian Ocean the wind blows from the southwest in summer and from the northeast in winter.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.3 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.1 (grade 5) · +3 more
A seasonal reversal of the prevailing wind over a large region. The word comes from the Arabic mawsim, “season,” through the Portuguese monção. In the northern Indian Ocean the wind blows from the southwest in summer and from the northeast in winter.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.3 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.1 (grade 5) · +3 more
Montreux ConventionEnglish
The treaty of 1936 that gives Turkey control of the Turkish Straits, guarantees free passage for merchant ships in peacetime, and limits the passage of warships.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
The treaty of 1936 that gives Turkey control of the Turkish Straits, guarantees free passage for merchant ships in peacetime, and limits the passage of warships.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
Mosi-oa-TunyaEnglish
The local name for Victoria Falls, meaning “the smoke that thunders.”
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.2 (grade 5)
The local name for Victoria Falls, meaning “the smoke that thunders.”
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.2 (grade 5)
mountain passEnglish
A low gap between mountains where people can cross more easily.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.2 (grade 3) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.1 (grade 4)
A low gap between mountains where people can cross more easily.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.2 (grade 3) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.1 (grade 4)
mountain rootEnglish
The thick part of the crust that reaches deep into the mantle beneath a high mountain range, like the hidden part of an iceberg.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.3 (grade 6)
The thick part of the crust that reaches deep into the mantle beneath a high mountain range, like the hidden part of an iceberg.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.3 (grade 6)
mouth (of a river)English
The place where a river flows into a sea, ocean or lake.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.3 (grade 4)
The place where a river flows into a sea, ocean or lake.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 4.3 (grade 4)
multiple-nuclei modelEnglish
The model of Chauncy Harris and Edward Ullman (1945) in which a city grows around several separate centers (nuclei), such as a port, an industrial district or an outlying business district, as well as the CBD.
Human Geography, Lesson 7.3 (grade 9–12)
The model of Chauncy Harris and Edward Ullman (1945) in which a city grows around several separate centers (nuclei), such as a port, an industrial district or an outlying business district, as well as the CBD.
Human Geography, Lesson 7.3 (grade 9–12)
multistate nationEnglish
A nation whose people live in two or more states, such as the Koreans in North and South Korea.
Human Geography, Lesson 5.1 (grade 9–12)
A nation whose people live in two or more states, such as the Koreans in North and South Korea.
Human Geography, Lesson 5.1 (grade 9–12)
multi-tubular boilerEnglish
A boiler in which many small tubes carry hot gases from the fire through the water. More tube surface means more heat reaches the water, so the engine makes steam faster. Rocket had 25 copper tubes.
Technology Overcoming Geography, Lesson 2.3 (grade 9–12)
A boiler in which many small tubes carry hot gases from the fire through the water. More tube surface means more heat reaches the water, so the engine makes steam faster. Rocket had 25 copper tubes.
Technology Overcoming Geography, Lesson 2.3 (grade 9–12)
mutinyEnglish
When sailors or officers rise up against their captain and try to take over the ship.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3)
When sailors or officers rise up against their captain and try to take over the ship.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3)
N
nationEnglish
A large group of people who see themselves as one people because of a shared language, history, faith, customs or ancestry. A nation is a people, not a territory.
Human Geography, Lesson 5.1 (grade 9–12)
A large group of people who see themselves as one people because of a shared language, history, faith, customs or ancestry. A nation is a people, not a territory.
Human Geography, Lesson 5.1 (grade 9–12)
nation and stateEnglish
A nation is a people bound by language, memory and faith; a state is a government ruling a territory. From 1795 to 1918 the Polish nation lived on without a Polish state.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
A nation is a people bound by language, memory and faith; a state is a government ruling a territory. From 1795 to 1918 the Polish nation lived on without a Polish state.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
national characterEnglish
Mahan’s term for a people’s habits and aptitudes, especially a bent for trade and enterprise at sea. Today historians treat such generalizations about whole peoples with caution.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
Mahan’s term for a people’s habits and aptitudes, especially a bent for trade and enterprise at sea. Today historians treat such generalizations about whole peoples with caution.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
nationalizationEnglish
A government taking ownership of a private company or property, as Egypt did with the Suez Canal Company in 1956.
Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
A government taking ownership of a private company or property, as Egypt did with the Suez Canal Company in 1956.
Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
nation-stateEnglish
A state whose territory closely matches the homeland of one nation, such as Japan or Iceland.
Human Geography, Lesson 5.1 (grade 9–12)
A state whose territory closely matches the homeland of one nation, such as Japan or Iceland.
Human Geography, Lesson 5.1 (grade 9–12)
natural barrierEnglish
A sea, mountain range, desert, marsh or great forest that makes movement slow, costly or dangerous.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 1.1 (grade 7)
A sea, mountain range, desert, marsh or great forest that makes movement slow, costly or dangerous.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 1.1 (grade 7)
natural borderEnglish
A boundary that follows a physical feature such as a river, ridgeline, desert or sea (Units 2–5).
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
A boundary that follows a physical feature such as a river, ridgeline, desert or sea (Units 2–5).
Geography and History: Why Borders Fall Where They Do, Lesson 10.5 (grade 9–12)
natural frontierEnglish
The idea that a nation’s proper border is a feature of nature such as a river, mountain range or sea. French writers applied it to the Rhine.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
The idea that a nation’s proper border is a feature of nature such as a river, mountain range or sea. French writers applied it to the Rhine.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
natural harborEnglish
A stretch of deep water sheltered from wind and waves by the land itself, where ships can anchor and tie up safely.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.4 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
A stretch of deep water sheltered from wind and waves by the land itself, where ships can anchor and tie up safely.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.4 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
natural hazardEnglish
A natural event, such as a hurricane, flood, earthquake, tornado, wildfire or drought, that can threaten people and property.
Human Geography, Lesson 9.4 (grade 9–12)
A natural event, such as a hurricane, flood, earthquake, tornado, wildfire or drought, that can threaten people and property.
Human Geography, Lesson 9.4 (grade 9–12)
natural resourceEnglish
Something useful that God placed in nature, such as soil, water, timber, coal, iron or fish.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.3 (grade 4) · Human Geography, Lesson 9.1 (grade 9–12)
Something useful that God placed in nature, such as soil, water, timber, coal, iron or fish.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.3 (grade 4) · Human Geography, Lesson 9.1 (grade 9–12)
naturalizationEnglish
The legal process by which an immigrant becomes a citizen.
Human Geography, Lesson 3.4 (grade 9–12)
The legal process by which an immigrant becomes a citizen.
Human Geography, Lesson 3.4 (grade 9–12)
Nautical AlmanacEnglish
A yearly book of tables of the sun, moon and stars for navigators, first published in Britain for the year 1767 under Nevil Maskelyne, the Astronomer Royal.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
A yearly book of tables of the sun, moon and stars for navigators, first published in Britain for the year 1767 under Nevil Maskelyne, the Astronomer Royal.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
nautical chartEnglish
A map made for sailors that shows coasts, depths, dangers and, on some charts, currents.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.1 (grade 6)
A map made for sailors that shows coasts, depths, dangers and, on some charts, currents.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.1 (grade 6)
nautical mile and knotEnglish
A nautical mile is 1,852 m (about 1.15 ordinary miles), equal to one minute of latitude. A speed of one nautical mile per hour is one knot.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8)
A nautical mile is 1,852 m (about 1.15 ordinary miles), equal to one minute of latitude. A speed of one nautical mile per hour is one knot.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8)
naval mineEnglish
An explosive charge moored under the surface that blows up when a ship strikes it; cheap to lay and very hard to clear under fire.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
An explosive charge moored under the surface that blows up when a ship strikes it; cheap to lay and very hard to clear under fire.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
naval raceEnglish
A contest between nations to build more and better warships than each other, such as the Anglo-German race of about 1898–1914.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
A contest between nations to build more and better warships than each other, such as the Anglo-German race of about 1898–1914.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
Naval War CollegeEnglish
The U.S. Navy’s school for advanced study of strategy and history, founded at Newport, Rhode Island, in 1884 by Stephen B. Luce. Mahan’s lectures there became his famous book.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12)
The U.S. Navy’s school for advanced study of strategy and history, founded at Newport, Rhode Island, in 1884 by Stephen B. Luce. Mahan’s lectures there became his famous book.
Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12)
navigableEnglish
Deep and calm enough for boats or ships to travel on.
Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7)
Deep and calm enough for boats or ships to travel on.
Grade 7 Geography: Regions of the World, Lesson 4.1 (grade 7)
neighborEnglish
Someone who lives next to you. A country next to ours is a neighbor country.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1)
Someone who lives next to you. A country next to ours is a neighbor country.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1)
neighbor stateEnglish
A state that shares a border with your state.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.4 (grade 2) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.4 (grade 2)
A state that shares a border with your state.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.4 (grade 2) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.4 (grade 2)
neighborhoodEnglish
The houses, streets and places close to your home, and the people who live there.
Grade 1 Geography: Maps and Journeys, Lesson 1.4 (grade 1)
The houses, streets and places close to your home, and the people who live there.
Grade 1 Geography: Maps and Journeys, Lesson 1.4 (grade 1)
NeopanamaxEnglish
The largest ship that fits the new Panama locks opened in 2016: about 366 m (1,200 ft) long and 49 m (161 ft) wide, with about 15.2 m (50 ft) of draft.
Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
The largest ship that fits the new Panama locks opened in 2016: about 366 m (1,200 ft) long and 49 m (161 ft) wide, with about 15.2 m (50 ft) of draft.
Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
net migration rateEnglish
Immigrants minus emigrants in a year, per 1,000 people in the population.
Human Geography, Lesson 3.1 (grade 9–12)
Immigrants minus emigrants in a year, per 1,000 people in the population.
Human Geography, Lesson 3.1 (grade 9–12)
neutralityEnglish
A state’s policy of taking no side in other nations’ wars. The great powers recognized Swiss neutrality in 1815.
Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12)
A state’s policy of taking no side in other nations’ wars. The great powers recognized Swiss neutrality in 1815.
Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12)
New EnglandEnglish
The six states in the northeast corner of the United States: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island and Connecticut.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.1 (grade 4)
The six states in the northeast corner of the United States: Maine, New Hampshire, Vermont, Massachusetts, Rhode Island and Connecticut.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.1 (grade 4)
New WorldEnglish
North and South America, the lands that were new to Europeans after 1492.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.2 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)
North and South America, the lands that were new to Europeans after 1492.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 4.2 (grade 5) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)
nomadEnglish
A person who moves with herds of animals from pasture to pasture through the seasons instead of living in one place.
Grade 7 Geography: Regions of the World, Lesson 2.4 (grade 7)
A person who moves with herds of animals from pasture to pasture through the seasons instead of living in one place.
Grade 7 Geography: Regions of the World, Lesson 2.4 (grade 7)
nonalignmentEnglish
The policy of states, such as India under Nehru, that refused to join either Cold War bloc. Leaders of many such states met at Bandung, Indonesia, in 1955.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
The policy of states, such as India under Nehru, that refused to join either Cold War bloc. Leaders of many such states met at Bandung, Indonesia, in 1955.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
non-colonizationEnglish
The principle that the American continents were no longer open to new colonies by any European power.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
The principle that the American continents were no longer open to new colonies by any European power.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
nonrenewable resourceEnglish
A resource that exists in a fixed amount and does not grow back, such as coal, iron ore and oil.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.3 (grade 4) · Human Geography, Lesson 9.1 (grade 9–12)
A resource that exists in a fixed amount and does not grow back, such as coal, iron ore and oil.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.3 (grade 4) · Human Geography, Lesson 9.1 (grade 9–12)
Nordic crossEnglish
A cross set off-center toward the flagpole, used on the flags of Denmark, Norway, Sweden, Finland and Iceland.
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
A cross set off-center toward the flagpole, used on the flags of Denmark, Norway, Sweden, Finland and Iceland.
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
normalizationEnglish
Dividing a count by a base such as area or population (people per square mile, deaths per 10,000) so that places of different sizes can be compared fairly.
Human Geography, Lesson 1.3 (grade 9–12)
Dividing a count by a base such as area or population (people per square mile, deaths per 10,000) so that places of different sizes can be compared fairly.
Human Geography, Lesson 1.3 (grade 9–12)
NorseEnglish
The people of long ago from Norway and the lands nearby. Some of them were the sea raiders we call Vikings.
Grade 1 Geography: Maps and Journeys, Lesson 8.1 (grade 1)
The people of long ago from Norway and the lands nearby. Some of them were the sea raiders we call Vikings.
Grade 1 Geography: Maps and Journeys, Lesson 8.1 (grade 1)
northEnglish
The direction toward the North Pole. On a globe and on most maps, north is up.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 2.4 (grade K)
The direction toward the North Pole. On a globe and on most maps, north is up.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 2.4 (grade K)
North Atlantic DriftEnglish
The warm current that carries water of the Gulf Stream northeast across the Atlantic toward the British Isles and Norway.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
The warm current that carries water of the Gulf Stream northeast across the Atlantic toward the British Isles and Norway.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.4 (grade 6)
North Atlantic Treaty Organization (NATO)English
A military alliance founded in 1949 under which members agree that an armed attack on one is an attack on all (Article 5); 32 members as of 2026, headquartered in Brussels.
Human Geography, Lesson 5.4 (grade 9–12)
A military alliance founded in 1949 under which members agree that an armed attack on one is an attack on all (Article 5); 32 members as of 2026, headquartered in Brussels.
Human Geography, Lesson 5.4 (grade 9–12)
North China PlainEnglish
The great flat lowland of northern China, built largely of Yellow River silt, between the mountains and the sea.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.4 (grade 8)
The great flat lowland of northern China, built largely of Yellow River silt, between the mountains and the sea.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.4 (grade 8)
North European PlainEnglish
The great lowland that stretches from southwestern France through Belgium, the Netherlands, northern Germany, Denmark and Poland, and widens eastward into the East European Plain of Belarus and Russia.
Grade 7 Geography: Regions of the World, Lesson 1.1 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
The great lowland that stretches from southwestern France through Belgium, the Netherlands, northern Germany, Denmark and Poland, and widens eastward into the East European Plain of Belarus and Russia.
Grade 7 Geography: Regions of the World, Lesson 1.1 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
north, south, east and westEnglish
The four main directions. We use them everywhere on the earth.
Grade 1 Geography: Maps and Journeys, Lesson 2.1 (grade 1)
The four main directions. We use them everywhere on the earth.
Grade 1 Geography: Maps and Journeys, Lesson 2.1 (grade 1)
North Star (Polaris)English
The star that sits almost exactly above the North Pole. It hardly moves all night, so facing it means facing north.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.1 (grade 3)
The star that sits almost exactly above the North Pole. It hardly moves all night, so facing it means facing north.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.1 (grade 3)
North WoodsEnglish
The great cold forests of pine, spruce and birch in the far north of states like Minnesota, Wisconsin, Michigan and Maine.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.2 (grade 2)
The great cold forests of pine, spruce and birch in the far north of states like Minnesota, Wisconsin, Michigan and Maine.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.2 (grade 2)
northeast monsoonEnglish
The winter monsoon, about November to March: drier, steadier winds from the northeast that carry ships from India toward Arabia and East Africa.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
The winter monsoon, about November to March: drier, steadier winds from the northeast that carry ships from India toward Arabia and East Africa.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
Northwest PassageEnglish
A water road over the top of North America from the Atlantic to the Pacific that explorers searched for over hundreds of years.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.3 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
A water road over the top of North America from the Atlantic to the Pacific that explorers searched for over hundreds of years.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.3 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.4 (grade 5)
not after (terminus ante quem)English
The latest date a map could have been made, set by something it still shows that later changed or something it does not yet show.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
The latest date a map could have been made, set by something it still shows that later changed or something it does not yet show.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
not before (terminus post quem)English
The earliest date a map could have been made, set by the newest thing it shows.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
The earliest date a map could have been made, set by the newest thing it shows.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.3 (grade 8)
number of populationEnglish
For Mahan, not the total population but the number of people who follow the sea or could quickly be trained for it: sailors, shipbuilders and dock workers.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
For Mahan, not the total population but the number of people who follow the sea or could quickly be trained for it: sailors, shipbuilders and dock workers.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
nutmeg and maceEnglish
Two spices from the same fruit of the nutmeg tree: nutmeg is the hard seed, and mace is the red, lacy covering (aril) around it.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
Two spices from the same fruit of the nutmeg tree: nutmeg is the hard seed, and mace is the red, lacy covering (aril) around it.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
O
oceanEnglish
A very big, very deep body of salt water. The Atlantic Ocean lies between Europe and America.
Grade 1 Geography: Maps and Journeys, Lesson 8.2 (grade 1) · Grade 1 Geography: Maps and Journeys, Lesson 9.4 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.1 (grade 3) · +3 more
A very big, very deep body of salt water. The Atlantic Ocean lies between Europe and America.
Grade 1 Geography: Maps and Journeys, Lesson 8.2 (grade 1) · Grade 1 Geography: Maps and Journeys, Lesson 9.4 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.1 (grade 3) · +3 more
Oder–Neisse lineEnglish
Poland’s western border since 1945, following the Oder River and its tributary the Lusatian Neisse from the Baltic to the Czech border.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
Poland’s western border since 1945, following the Oder River and its tributary the Lusatian Neisse from the Baltic to the Czech border.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
offshore islands and continentsEnglish
Spykman’s term for lands just off Eurasia (Britain and Japan) and the more distant land masses beyond (Africa and Australia), which sea power can use as bases against the mainland.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
Spykman’s term for lands just off Eurasia (Britain and Japan) and the more distant land masses beyond (Africa and Australia), which sea power can use as bases against the mainland.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12)
old and new immigrationEnglish
Historians’ terms for the earlier wave from northern and western Europe (Ireland, Germany, Britain, Scandinavia) and the later wave, after about 1880, from southern and eastern Europe (Italy, Austria-Hungary, the Russian Empire, Greece).
Human Geography, Lesson 3.2 (grade 9–12)
Historians’ terms for the earlier wave from northern and western Europe (Ireland, Germany, Britain, Scandinavia) and the later wave, after about 1880, from southern and eastern Europe (Italy, Austria-Hungary, the Russian Empire, Greece).
Human Geography, Lesson 3.2 (grade 9–12)
Old WorldEnglish
Europe, Africa and Asia, the lands Europeans knew before 1492.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)
Europe, Africa and Asia, the lands Europeans knew before 1492.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)
Operation BarbarossaEnglish
Nazi Germany’s invasion of the Soviet Union, launched on 22 June 1941, named after the medieval German emperor Frederick Barbarossa.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
Nazi Germany’s invasion of the Soviet Union, launched on 22 June 1941, named after the medieval German emperor Frederick Barbarossa.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
operatorEnglish
The person who taps out the code at one end of the wire and reads it at the other end.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.1 (grade 2)
The person who taps out the code at one end of the wire and reads it at the other end.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.1 (grade 2)
opiumEnglish
A habit-forming drug made from poppies. British merchants shipped it from India and sold it in China in the 1800s, doing great harm.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
A habit-forming drug made from poppies. British merchants shipped it from India and sold it in China in the 1800s, doing great harm.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
order of goodsEnglish
The rank of a good or service: low-order goods (bread, gasoline) are bought often and have small thresholds and ranges; high-order goods (heart surgery, pianos, opera) are bought rarely and need large thresholds and long ranges.
Human Geography, Lesson 7.2 (grade 9–12)
The rank of a good or service: low-order goods (bread, gasoline) are bought often and have small thresholds and ranges; high-order goods (heart surgery, pianos, opera) are bought rarely and need large thresholds and long ranges.
Human Geography, Lesson 7.2 (grade 9–12)
OrdosEnglish
The grassland and desert inside the great northward loop of the Yellow River, long fought over by Chinese dynasties and steppe peoples.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
The grassland and desert inside the great northward loop of the Yellow River, long fought over by Chinese dynasties and steppe peoples.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
ore boatEnglish
A long cargo ship, also called a lake freighter, that carries iron ore across the Great Lakes.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
A long cargo ship, also called a lake freighter, that carries iron ore across the Great Lakes.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.1 (grade 4)
Oregon CountryEnglish
The region between Spanish (later Mexican) California at 42°N and Russian America at 54°40′N, from the Rocky Mountains to the Pacific, claimed by both the United States and Britain.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
The region between Spanish (later Mexican) California at 42°N and Russian America at 54°40′N, from the Rocky Mountains to the Pacific, claimed by both the United States and Britain.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
Oregon TreatyEnglish
The treaty signed June 15, 1846, that divided the Oregon Country between the United States and Britain along the 49th parallel to the sea channel, giving all of Vancouver Island to Britain.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
The treaty signed June 15, 1846, that divided the Oregon Country between the United States and Britain along the 49th parallel to the sea channel, giving all of Vancouver Island to Britain.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
organic theory of the stateEnglish
The idea, set out by Kjellén and others, that a state is like a living organism that must grow; a metaphor later used to excuse conquest.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
The idea, set out by Kjellén and others, that a state is like a living organism that must grow; a metaphor later used to excuse conquest.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
orienteeringEnglish
A sport and skill of finding your way from point to point across land with a map and a compass.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.4 (grade 5) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8)
A sport and skill of finding your way from point to point across land with a map and a compass.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.4 (grade 5) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8)
orographic precipitationEnglish
Rain or snow caused when wind pushes moist air up the slope of a mountain, cooling it until its water vapor condenses.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6)
Rain or snow caused when wind pushes moist air up the slope of a mountain, cooling it until its water vapor condenses.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6)
orographic rainEnglish
Rain made when moist wind is forced up a mountainside, cools and drops its water.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
Rain made when moist wind is forced up a mountainside, cools and drops its water.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
ortoqEnglish
A merchant partnership in which Mongol nobles invested money with merchants, often Muslim or Uyghur, who traded on their behalf and shared the profits.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.4 (grade 9–12)
A merchant partnership in which Mongol nobles invested money with merchants, often Muslim or Uyghur, who traded on their behalf and shared the profits.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.4 (grade 9–12)
OutbackEnglish
The huge, dry, mostly empty middle of Australia, far from the coast.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.3 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
The huge, dry, mostly empty middle of Australia, far from the coast.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.3 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
outer or insular crescentEnglish
The ring of islands and overseas lands, “wholly oceanic”: Britain, Japan, the Americas, southern Africa and Australia.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
The ring of islands and overseas lands, “wholly oceanic”: Britain, Japan, the Americas, southern Africa and Australia.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
overlayEnglish
A transparent copy of one map laid on top of another so the two can be compared.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
A transparent copy of one map laid on top of another so the two can be compared.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.4 (grade 8)
overstretchEnglish
Taking on more commitments than a nation’s power can sustain, a danger Lippmann saw in a policy of defending every point on the Eurasian rim.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
Taking on more commitments than a nation’s power can sustain, a danger Lippmann saw in a policy of defending every point on the Eurasian rim.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
oxbow lakeEnglish
A curved lake left behind when a river cuts across the neck of a meander and abandons the old loop.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6)
A curved lake left behind when a river cuts across the neck of a meander and abandons the old loop.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6)
oxenEnglish
Big, strong, patient cattle trained to pull wagons and plows.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.2 (grade 2)
Big, strong, patient cattle trained to pull wagons and plows.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.2 (grade 2)
P
P wave and S waveEnglish
P (primary) waves push and pull the rock, travel fastest and pass through solids and liquids. S (secondary) waves shake the rock side to side, travel slower and cannot pass through liquids.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.1 (grade 6)
P (primary) waves push and pull the rock, travel fastest and pass through solids and liquids. S (secondary) waves shake the rock side to side, travel slower and cannot pass through liquids.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.1 (grade 6)
Pacific OceanEnglish
The biggest ocean on earth. It is on the west coast of our country.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.4 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.1 (grade 3) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3) · +1 more
The biggest ocean on earth. It is on the west coast of our country.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.4 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.1 (grade 3) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3) · +1 more
Pacific Railway ActEnglish
The law signed by President Lincoln on July 1, 1862, that chartered the Union Pacific and authorized the Central Pacific to build a railroad and telegraph to the Pacific, with grants of land and loans of government bonds.
Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12) · Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
The law signed by President Lincoln on July 1, 1862, that chartered the Union Pacific and authorized the Central Pacific to build a railroad and telegraph to the Pacific, with grants of land and loans of government bonds.
Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12) · Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
pacing planEnglish
A set of time checkpoints for an exam (for example, question 20 by minute 20) that keeps you from running out of time.
Human Geography, Lesson 10.4 (grade 9–12)
A set of time checkpoints for an exam (for example, question 20 by minute 20) that keeps you from running out of time.
Human Geography, Lesson 10.4 (grade 9–12)
pack iceEnglish
Sea ice broken into floes that crowd together and drift with the wind and currents.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
Sea ice broken into floes that crowd together and drift with the wind and currents.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
paddle steamerEnglish
A steamship driven by large paddle wheels on its sides (or stern), turned by a steam engine. Most early ocean steamers were paddle steamers that also carried sails.
Technology Overcoming Geography, Lesson 1.4 (grade 9–12)
A steamship driven by large paddle wheels on its sides (or stern), turned by a steam engine. Most early ocean steamers were paddle steamers that also carried sails.
Technology Overcoming Geography, Lesson 1.4 (grade 9–12)
padrãoEnglish
A stone pillar topped with a cross and carved with the royal arms, set up by Portuguese captains to mark the farthest point they reached.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5)
A stone pillar topped with a cross and carved with the royal arms, set up by Portuguese captains to mark the farthest point they reached.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.2 (grade 5)
PampasEnglish
The wide, flat, fertile grasslands of Argentina and Uruguay, famous for cattle, wheat and the gauchos who herded on horseback.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
The wide, flat, fertile grasslands of Argentina and Uruguay, famous for cattle, wheat and the gauchos who herded on horseback.
Grade 7 Geography: Regions of the World, Lesson 8.4 (grade 7)
PanamaxEnglish
The largest size of ship that could fit the original Panama Canal locks, which are 33.5 m (110 ft) wide and 305 m (1,000 ft) long.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12) · Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
The largest size of ship that could fit the original Panama Canal locks, which are 33.5 m (110 ft) wide and 305 m (1,000 ft) long.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12) · Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
Panamax and NeopanamaxEnglish
The largest ship sizes that fit the original Panama locks (about 32.3 m or 106 ft wide) and the larger locks opened in 2016 (about 51 m or 168 ft wide). Ships are designed to these limits.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12)
The largest ship sizes that fit the original Panama locks (about 32.3 m or 106 ft wide) and the larger locks opened in 2016 (about 51 m or 168 ft wide). Ships are designed to these limits.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12)
pan-regionsEnglish
Haushofer’s scheme of a few great north–south blocs (such as Pan-America, Eur-Africa and Pan-Asia), each dominated by one great power.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
Haushofer’s scheme of a few great north–south blocs (such as Pan-America, Eur-Africa and Pan-Asia), each dominated by one great power.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
papal bullEnglish
A formal decree issued by a pope, named for the lead seal (Latin bulla) attached to it. Alexander VI’s bull Inter caetera of 1493 drew the first line.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
A formal decree issued by a pope, named for the lead seal (Latin bulla) attached to it. Alexander VI’s bull Inter caetera of 1493 drew the first line.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
parallel of latitudeEnglish
An east–west line connecting all points at the same angle north or south of the equator; easy to describe in a treaty and to find by observing the stars.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
An east–west line connecting all points at the same angle north or south of the equator; easy to describe in a treaty and to find by observing the stars.
Geography and History: Why Borders Fall Where They Do, Lesson 8.3 (grade 9–12)
pastoral nomadismEnglish
A way of life based on herding animals and moving with them between seasonal pastures rather than farming fixed fields.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12) · Human Geography, Lesson 6.4 (grade 9–12)
A way of life based on herding animals and moving with them between seasonal pastures rather than farming fixed fields.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12) · Human Geography, Lesson 6.4 (grade 9–12)
perimeter defenseEnglish
Resisting expansion at every point along a frontier, wherever it occurs. NSC-68 (1950) moved American policy in this direction.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
Resisting expansion at every point along a frontier, wherever it occurs. NSC-68 (1950) moved American policy in this direction.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
Periplus of the Erythraean SeaEnglish
A Greek merchant’s guide written in the first century A.D., listing the ports, goods and sailing seasons of the Red Sea, Arabia, East Africa and India.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
A Greek merchant’s guide written in the first century A.D., listing the ports, goods and sailing seasons of the Red Sea, Arabia, East Africa and India.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
perspective mapEnglish
A map drawn as if the earth were seen from a point far out in space, so the curve of the globe shows. Harrison made many of these.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
A map drawn as if the earth were seen from a point far out in space, so the curve of the globe shows. Harrison made many of these.
Geopolitics: The Great Ideas, Lesson 4.4 (grade 9–12)
persuasive mapEnglish
A map designed mainly to convince the viewer of an argument, through its center, colors, arrows, symbols and what it leaves out.
Geopolitics: The Great Ideas, Lesson 1.4 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
A map designed mainly to convince the viewer of an argument, through its center, colors, arrows, symbols and what it leaves out.
Geopolitics: The Great Ideas, Lesson 1.4 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12)
peso de ocho (piece of eight)English
The Spanish silver coin worth eight reales, weighing about 27 g (just under 1 oz), minted in Mexico and Peru and used as trade money across the world.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12)
The Spanish silver coin worth eight reales, weighing about 27 g (just under 1 oz), minted in Mexico and Peru and used as trade money across the world.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12)
Phillips ChannelEnglish
The narrowest part of the shipping lane in the Singapore Strait, only about 1.7 miles (2.8 km) wide.
Geography and History: Why Borders Fall Where They Do, Lesson 6.3 (grade 9–12)
The narrowest part of the shipping lane in the Singapore Strait, only about 1.7 miles (2.8 km) wide.
Geography and History: Why Borders Fall Where They Do, Lesson 6.3 (grade 9–12)
physical conformationEnglish
The shape and nature of a country’s coast and land: its harbors, rivers leading inland, soil and climate, which can draw a people toward the sea or keep them at home.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
The shape and nature of a country’s coast and land: its harbors, rivers leading inland, soil and climate, which can draw a people toward the sea or keep them at home.
Geopolitics: The Great Ideas, Lesson 2.2 (grade 9–12)
physical factEnglish
A measurable feature of the land, water or climate: a river’s length, a strait’s width, a sea’s depth, a pass’s height, a harbor’s ice season. Physical facts can be checked by anyone with the right tools.
Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12)
A measurable feature of the land, water or climate: a river’s length, a strait’s width, a sea’s depth, a pass’s height, a harbor’s ice season. Physical facts can be checked by anyone with the right tools.
Geopolitics: The Great Ideas, Lesson 5.2 (grade 9–12)
physical mapEnglish
A map that shows the land and water God made: mountains, plains, valleys, rivers and lakes, often with colors for height.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.3 (grade 4)
A map that shows the land and water God made: mountains, plains, valleys, rivers and lakes, often with colors for height.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.3 (grade 4)
physical (natural) boundaryEnglish
A border that follows a feature of the land or water, such as a river, the crest of a mountain range, a lake or a strait.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
A border that follows a feature of the land or water, such as a river, the crest of a mountain range, a lake or a strait.
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12)
physical regionEnglish
A part of a state or country where the land is much the same, such as a coastal plain or a mountain range.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.1 (grade 4)
A part of a state or country where the land is much the same, such as a coastal plain or a mountain range.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.1 (grade 4)
physiological densityEnglish
The number of people per unit of arable (farmable) land; it shows the pressure of population on the land that feeds it.
Human Geography, Lesson 10.2 (grade 9–12) · Human Geography, Lesson 2.1 (grade 9–12) · Human Geography, Lesson 6.1 (grade 9–12)
The number of people per unit of arable (farmable) land; it shows the pressure of population on the land that feeds it.
Human Geography, Lesson 10.2 (grade 9–12) · Human Geography, Lesson 2.1 (grade 9–12) · Human Geography, Lesson 6.1 (grade 9–12)
PiedmontEnglish
The rolling, hilly land of hard rock between the Appalachian Mountains and the fall line. The name means “foot of the mountain.”
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
The rolling, hilly land of hard rock between the Appalachian Mountains and the fall line. The name means “foot of the mountain.”
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.3 (grade 4) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
Pillars of HerculesEnglish
The ancient name for the two great rocks that guard the Strait of Gibraltar: the Rock of Gibraltar in Europe and a mountain on the African shore.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
The ancient name for the two great rocks that guard the Strait of Gibraltar: the Rock of Gibraltar in Europe and a mountain on the African shore.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
pipelineEnglish
A long pipe that carries oil or gas over land, sometimes used to go around a choke point.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.3 (grade 8)
A long pipe that carries oil or gas over land, sometimes used to go around a choke point.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.3 (grade 8)
pipeline throughputEnglish
The volume a pipeline moves in a period, usually in barrels a day for oil or cubic meters (or cubic feet) a day for gas.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
The volume a pipeline moves in a period, usually in barrels a day for oil or cubic meters (or cubic feet) a day for gas.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
pivot areaEnglish
Mackinder’s 1904 name for the vast interior of Eurasia, “wholly continental,” whose rivers drain to the Arctic or to inland seas and which ships cannot reach. In 1919 he called it the Heartland.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
Mackinder’s 1904 name for the vast interior of Eurasia, “wholly continental,” whose rivers drain to the Arctic or to inland seas and which ships cannot reach. In 1919 he called it the Heartland.
Geopolitics: The Great Ideas, Lesson 3.1 (grade 9–12)
plainEnglish
Wide land that is flat or gently rolling, with no mountains.
Grade 1 Geography: Maps and Journeys, Lesson 3.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.2 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.1 (grade 3) · +2 more
Wide land that is flat or gently rolling, with no mountains.
Grade 1 Geography: Maps and Journeys, Lesson 3.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.2 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.1 (grade 3) · +2 more
plainsEnglish
Wide, flat land covered with grass. The Great Plains are in the middle of North America.
Grade 1 Geography: Maps and Journeys, Lesson 7.3 (grade 1) · Grade 1 Geography: Maps and Journeys, Lesson 8.4 (grade 1)
Wide, flat land covered with grass. The Great Plains are in the middle of North America.
Grade 1 Geography: Maps and Journeys, Lesson 7.3 (grade 1) · Grade 1 Geography: Maps and Journeys, Lesson 8.4 (grade 1)
plank houseEnglish
A big house made of wide, flat boards split from cedar logs, where several families lived.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.4 (grade 2)
A big house made of wide, flat boards split from cedar logs, where several families lived.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.4 (grade 2)
planned capitalEnglish
A capital city built on purpose, often on a new site, to serve as the seat of a national government (for example, Washington, Canberra, Brasília and Abuja).
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
A capital city built on purpose, often on a new site, to serve as the seat of a national government (for example, Washington, Canberra, Brasília and Abuja).
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
Point of BeginningEnglish
The spot on the Ohio River where the first survey of the public lands was begun in 1785.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.4 (grade 4)
The spot on the Ohio River where the first survey of the public lands was begun in 1785.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.4 (grade 4)
polar desertEnglish
A cold place that gets very little snow or rain each year. Antarctica is the biggest one.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.4 (grade 3)
A cold place that gets very little snow or rain each year. Antarctica is the biggest one.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.4 (grade 3)
polar plateauEnglish
The high, flat, very cold ice sheet in the middle of Antarctica, on which the South Pole stands.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5)
The high, flat, very cold ice sheet in the middle of Antarctica, on which the South Pole stands.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5)
polar projectionEnglish
A map centered on a pole, on which meridians appear as straight lines radiating from the center and parallels as circles.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
A map centered on a pole, on which meridians appear as straight lines radiating from the center and parallels as circles.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
polar routeEnglish
An air route that crosses the Arctic to follow the great circle between distant cities, such as Copenhagen to Los Angeles or Europe to Tokyo.
Technology Overcoming Geography, Lesson 4.4 (grade 9–12)
An air route that crosses the Arctic to follow the great circle between distant cities, such as Copenhagen to Los Angeles or Europe to Tokyo.
Technology Overcoming Geography, Lesson 4.4 (grade 9–12)
Polaris (the North Star)English
A star that sits almost exactly above the North Pole, so it seems to stay still while the other stars circle around it during the night.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.1 (grade 5)
A star that sits almost exactly above the North Pole, so it seems to stay still while the other stars circle around it during the night.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.1 (grade 5)
polderEnglish
A piece of low land surrounded by dikes and kept dry by pumping. Many Dutch polders were once lakes, marshes or seabed.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.1 (grade 6)
A piece of low land surrounded by dikes and kept dry by pumping. Many Dutch polders were once lakes, marshes or seabed.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.1 (grade 6)
polisEnglish
A Greek city-state: a city and the farmland around it, governing itself with its own laws, gods, army and citizens (plural poleis).
Geography and History: Why Borders Fall Where They Do, Lesson 5.4 (grade 9–12)
A Greek city-state: a city and the farmland around it, governing itself with its own laws, gods, army and citizens (plural poleis).
Geography and History: Why Borders Fall Where They Do, Lesson 5.4 (grade 9–12)
Polish–Lithuanian CommonwealthEnglish
The union of the Kingdom of Poland and the Grand Duchy of Lithuania made permanent at Lublin in 1569; in the early 1600s one of the largest states in Europe.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
The union of the Kingdom of Poland and the Grand Duchy of Lithuania made permanent at Lublin in 1569; in the early 1600s one of the largest states in Europe.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
political mapEnglish
A map that shows the lines and places people have made: borders, states, counties, capitals and cities.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.3 (grade 4)
A map that shows the lines and places people have made: borders, states, counties, capitals and cities.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.3 (grade 4)
PolynesiaEnglish
The great triangle of Pacific islands between Hawaii, New Zealand and Easter Island, settled long ago by skilled canoe voyagers.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.1 (grade 5)
The great triangle of Pacific islands between Hawaii, New Zealand and Easter Island, settled long ago by skilled canoe voyagers.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.1 (grade 5)
Polynesia, Micronesia, MelanesiaEnglish
The three island regions of the Pacific. Polynesia means “many islands” (a great triangle from Hawaiʻi to New Zealand to Rapa Nui); Micronesia means “small islands” (north of the equator in the west); Melanesia means “black islands” (from New Guinea to Fiji).
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
The three island regions of the Pacific. Polynesia means “many islands” (a great triangle from Hawaiʻi to New Zealand to Rapa Nui); Micronesia means “small islands” (north of the equator in the west); Melanesia means “black islands” (from New Guinea to Fiji).
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
Polynesian TriangleEnglish
The huge triangle of Pacific islands with Hawaii, New Zealand and Easter Island (Rapa Nui) at its three corners.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.1 (grade 3)
The huge triangle of Pacific islands with Hawaii, New Zealand and Easter Island (Rapa Nui) at its three corners.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.1 (grade 3)
pondEnglish
A small, shallow lake. Frogs, ducks and lily pads like ponds.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.2 (grade K)
A small, shallow lake. Frogs, ducks and lily pads like ponds.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.2 (grade K)
population densityEnglish
The number of people per unit of land, such as people per square kilometer or per square mile.
Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7) · Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 7.2 (grade 8) · +2 more
The number of people per unit of land, such as people per square kilometer or per square mile.
Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7) · Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 7.2 (grade 8) · +2 more
population distributionEnglish
The pattern of where people live across an area: clustered, dispersed or strung out in a line (linear), such as along a river or a highway.
Human Geography, Lesson 2.1 (grade 9–12) · Statistics, Lesson 9.3 (grade 11–12)
The pattern of where people live across an area: clustered, dispersed or strung out in a line (linear), such as along a river or a highway.
Human Geography, Lesson 2.1 (grade 9–12) · Statistics, Lesson 9.3 (grade 11–12)
population momentumEnglish
The tendency of a young population to keep growing for decades after fertility falls to replacement level, because so many people are entering the childbearing years.
Human Geography, Lesson 2.4 (grade 9–12)
The tendency of a young population to keep growing for decades after fertility falls to replacement level, because so many people are entering the childbearing years.
Human Geography, Lesson 2.4 (grade 9–12)
population pyramidEnglish
A pair of back-to-back bar graphs showing the number or percentage of males and females in each age group, usually five-year bands, with the youngest at the bottom.
Human Geography, Lesson 2.4 (grade 9–12)
A pair of back-to-back bar graphs showing the number or percentage of males and females in each age group, usually five-year bands, with the youngest at the bottom.
Human Geography, Lesson 2.4 (grade 9–12)
population transferEnglish
The forced movement of whole peoples to fit new borders, as when millions of Germans were expelled from lands given to Poland and Poles were moved out of lands taken by the Soviet Union.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
The forced movement of whole peoples to fit new borders, as when millions of Germans were expelled from lands given to Poland and Poles were moved out of lands taken by the Soviet Union.
Geography and History: Why Borders Fall Where They Do, Lesson 7.2 (grade 9–12)
porphyry copper depositEnglish
A huge body of rock with copper minerals spread through it, formed with molten rock beneath mountain ranges such as the Andes and the Rockies; it is mined in giant open pits.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
A huge body of rock with copper minerals spread through it, formed with molten rock beneath mountain ranges such as the Andes and the Rockies; it is mined in giant open pits.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
port (outport)English
A harbor town that serves a larger city standing some distance inland, such as Piraeus for Athens or Leith for Edinburgh.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8)
A harbor town that serves a larger city standing some distance inland, such as Piraeus for Athens or Leith for Edinburgh.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.4 (grade 8)
portalEnglish
The entrance at each end of a tunnel.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7)
The entrance at each end of a tunnel.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7)
portolan chartEnglish
A sea chart of coasts and harbors drawn in the Middle Ages, covered with crisscross direction lines. The name comes from the Italian portolano, a book of directions from port to port.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.4 (grade 3) · Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
A sea chart of coasts and harbors drawn in the Middle Ages, covered with crisscross direction lines. The name comes from the Italian portolano, a book of directions from port to port.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.4 (grade 3) · Technology Overcoming Geography, Lesson 1.2 (grade 9–12)
position fixEnglish
A ship’s place worked out from measurements, given as latitude and longitude.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
A ship’s place worked out from measurements, given as latitude and longitude.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 3.4 (grade 5)
positive checksEnglish
In Malthus’s terms, causes that raise the death rate and hold population down: famine, disease, war and misery.
Human Geography, Lesson 2.3 (grade 9–12)
In Malthus’s terms, causes that raise the death rate and hold population down: famine, disease, war and misery.
Human Geography, Lesson 2.3 (grade 9–12)
possibilismEnglish
The view that the environment offers a range of possibilities and limits, and that people choose among them; named by Lucien Febvre in 1922.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
The view that the environment offers a range of possibilities and limits, and that people choose among them; named by Lucien Febvre in 1922.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
postcardEnglish
A stiff card with a picture on one side and room for a short note on the other. You mail it without an envelope.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.3 (grade 2)
A stiff card with a picture on one side and room for a short note on the other. You mail it without an envelope.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.3 (grade 2)
pound lockEnglish
A chamber with a gate at each end that is filled or emptied to raise or lower boats from one water level to another.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8) · Technology Overcoming Geography, Lesson 2.2 (grade 9–12)
A chamber with a gate at each end that is filled or emptied to raise or lower boats from one water level to another.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8) · Technology Overcoming Geography, Lesson 2.2 (grade 9–12)
power siteEnglish
A place where nature supplies usable energy, such as a waterfall or a fast stream that can turn a water wheel. Early mills were tied to power sites.
Human Geography, Lesson 8.1 (grade 9–12)
A place where nature supplies usable energy, such as a waterfall or a fast stream that can turn a water wheel. Early mills were tied to power sites.
Human Geography, Lesson 8.1 (grade 9–12)
pre-dreadnoughtEnglish
A battleship of about 1890–1906, usually carrying four heavy guns plus many smaller ones and driven by reciprocating steam engines. All the Great White Fleet’s battleships were of this kind.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
A battleship of about 1890–1906, usually carrying four heavy guns plus many smaller ones and driven by reciprocating steam engines. All the Great White Fleet’s battleships were of this kind.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
preservationEnglish
The view, associated with John Muir, that some wild places should be protected from development and kept as nearly untouched as possible.
Human Geography, Lesson 9.3 (grade 9–12)
The view, associated with John Muir, that some wild places should be protected from development and kept as nearly untouched as possible.
Human Geography, Lesson 9.3 (grade 9–12)
pressure ridgeEnglish
A wall of broken ice blocks pushed up where two sheets of sea ice crash together.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.1 (grade 5)
A wall of broken ice blocks pushed up where two sheets of sea ice crash together.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.1 (grade 5)
prevailing windsEnglish
The winds that blow most often from one direction in a region. Across most of the United States the prevailing winds blow from the west.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.2 (grade 6)
The winds that blow most often from one direction in a region. Across most of the United States the prevailing winds blow from the west.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.2 (grade 6)
preventive checksEnglish
In Malthus’s terms, causes that lower the birth rate, above all later marriage, which he called “moral restraint” from his second edition (1803).
Human Geography, Lesson 2.3 (grade 9–12)
In Malthus’s terms, causes that lower the birth rate, above all later marriage, which he called “moral restraint” from his second edition (1803).
Human Geography, Lesson 2.3 (grade 9–12)
price per ounceEnglish
The price of a package divided by the number of ounces in it. It lets you compare packages of different sizes fairly.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.4 (grade 5)
The price of a package divided by the number of ounces in it. It lets you compare packages of different sizes fairly.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.4 (grade 5)
primate cityEnglish
A city more than twice as large as the next-largest city of its country and far more important in its economy and culture (Mark Jefferson, 1939).
Human Geography, Lesson 7.1 (grade 9–12)
A city more than twice as large as the next-largest city of its country and far more important in its economy and culture (Mark Jefferson, 1939).
Human Geography, Lesson 7.1 (grade 9–12)
princely stateEnglish
One of more than 560 states in British India ruled by its own prince under British overlordship. In 1947 each ruler had to accede to India or Pakistan.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
One of more than 560 states in British India ruled by its own prince under British overlordship. In 1947 each ruler had to accede to India or Pakistan.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
principal meridian and baselineEnglish
The north–south and east–west survey lines that cross at an initial point. Every township and range in that survey district is counted from them.
Geography and History: Why Borders Fall Where They Do, Lesson 10.2 (grade 9–12)
The north–south and east–west survey lines that cross at an initial point. Every township and range in that survey district is counted from them.
Geography and History: Why Borders Fall Where They Do, Lesson 10.2 (grade 9–12)
Pripet MarshesEnglish
A huge region of forest, bog and slow rivers in southern Belarus and northern Ukraine (also called Polesia) that splits the eastern plain into a northern and a southern corridor.
Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
A huge region of forest, bog and slow rivers in southern Belarus and northern Ukraine (also called Polesia) that splits the eastern plain into a northern and a southern corridor.
Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12)
probabilismEnglish
The view that geography makes some outcomes more likely than others without making any of them certain.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12)
The view that geography makes some outcomes more likely than others without making any of them certain.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12)
Proclamation Line of 1763English
The boundary set by King George III on October 7, 1763, along the heads of the Atlantic rivers, beyond which colonists were forbidden to settle or to buy land from Indian nations.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
The boundary set by King George III on October 7, 1763, along the heads of the Atlantic rivers, beyond which colonists were forbidden to settle or to buy land from Indian nations.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
Promontory SummitEnglish
The place in Utah Territory, north of the Great Salt Lake, where the Central Pacific and Union Pacific tracks were joined on May 10, 1869.
Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
The place in Utah Territory, north of the Great Salt Lake, where the Central Pacific and Union Pacific tracks were joined on May 10, 1869.
Technology Overcoming Geography, Lesson 2.4 (grade 9–12)
proven reservesEnglish
The amount of oil that geologists are reasonably sure can be produced from known fields with present technology and prices.
Grade 7 Geography: Regions of the World, Lesson 3.4 (grade 7)
The amount of oil that geologists are reasonably sure can be produced from known fields with present technology and prices.
Grade 7 Geography: Regions of the World, Lesson 3.4 (grade 7)
provinceEnglish
One of the large parts into which a country is divided, each with its own capital. China in the 1800s had 18 provinces in its heartland.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
One of the large parts into which a country is divided, each with its own capital. China in the 1800s had 18 provinces in its heartland.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
puebloEnglish
A Spanish word for a town. It also means the Pueblo peoples and their homes of many rooms built side by side and stacked up like blocks.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2)
A Spanish word for a town. It also means the Pueblo peoples and their homes of many rooms built side by side and stacked up like blocks.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.3 (grade 2)
pull factorEnglish
A condition at a destination that attracts people, such as jobs, cheap land, freedom of worship or family already there.
Human Geography, Lesson 3.1 (grade 9–12)
A condition at a destination that attracts people, such as jobs, cheap land, freedom of worship or family already there.
Human Geography, Lesson 3.1 (grade 9–12)
Punic WarsEnglish
Three wars between Rome and Carthage (264–241, 218–201 and 149–146 B.C.) for control of the western Mediterranean.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
Three wars between Rome and Carthage (264–241, 218–201 and 149–146 B.C.) for control of the western Mediterranean.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
PuntEnglish
A land that ancient Egyptians reached by sea and traded with for incense, ebony, gold and animals; most scholars place it near the southern Red Sea.
Grade 7 Geography: Regions of the World, Lesson 9.3 (grade 7)
A land that ancient Egyptians reached by sea and traded with for incense, ebony, gold and animals; most scholars place it near the southern Red Sea.
Grade 7 Geography: Regions of the World, Lesson 9.3 (grade 7)
push factorEnglish
A condition at the place of origin that drives people away, such as famine, war, persecution or lack of work.
Human Geography, Lesson 3.1 (grade 9–12)
A condition at the place of origin that drives people away, such as famine, war, persecution or lack of work.
Human Geography, Lesson 3.1 (grade 9–12)
puzzle mapEnglish
A map cut into pieces that you fit back together.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.2 (grade K)
A map cut into pieces that you fit back together.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.2 (grade K)
Q
qanatEnglish
A gently sloping underground tunnel that carries groundwater from a hillside aquifer to fields and villages by gravity, with vertical shafts along its length.
Grade 7 Geography: Regions of the World, Lesson 3.2 (grade 7)
A gently sloping underground tunnel that carries groundwater from a hillside aquifer to fields and villages by gravity, with vertical shafts along its length.
Grade 7 Geography: Regions of the World, Lesson 3.2 (grade 7)
Qinling–Huai lineEnglish
The line of the Qinling Mountains and the Huai River, which roughly divides China’s colder, drier, wheat-growing north from its warmer, wetter, rice-growing south.
Grade 7 Geography: Regions of the World, Lesson 6.1 (grade 7)
The line of the Qinling Mountains and the Huai River, which roughly divides China’s colder, drier, wheat-growing north from its warmer, wetter, rice-growing south.
Grade 7 Geography: Regions of the World, Lesson 6.1 (grade 7)
quayEnglish
The solid wharf wall where a ship ties up to load and unload (pronounced “key”). The place along it where one ship lies is a berth.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
The solid wharf wall where a ship ties up to load and unload (pronounced “key”). The place along it where one ship lies is a berth.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
R
Radcliffe LineEnglish
The boundary between India and Pakistan in the Punjab and in Bengal, drawn by Sir Cyril Radcliffe as chairman of the two boundary commissions and published on August 17, 1947.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
The boundary between India and Pakistan in the Punjab and in Bengal, drawn by Sir Cyril Radcliffe as chairman of the two boundary commissions and published on August 17, 1947.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
rail gaugeEnglish
The distance between the two rails. Russia used a broad gauge of 5 feet (1,524 mm); most of Europe used 1,435 mm, so trains could not run straight through at the border.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12)
The distance between the two rails. Russia used a broad gauge of 5 feet (1,524 mm); most of Europe used 1,435 mm, so trains could not run straight through at the border.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12)
railheadEnglish
A town at the end of a railroad line, or on a line, where goods and animals are loaded onto trains.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 4.4 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12)
A town at the end of a railroad line, or on a line, where goods and animals are loaded onto trains.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4) · Grade 7 Geography: Regions of the World, Lesson 4.4 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12)
railroadEnglish
A road made of two iron rails laid on wooden ties, for trains to run on.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.2 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.1 (grade 4)
A road made of two iron rails laid on wooden ties, for trains to run on.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.2 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.1 (grade 4)
rain beltEnglish
The band of rising air and heavy rain near the equator (geographers call it the Intertropical Convergence Zone, or ITCZ). It follows the overhead sun north and south during the year.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
The band of rising air and heavy rain near the equator (geographers call it the Intertropical Convergence Zone, or ITCZ). It follows the overhead sun north and south during the year.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
rain forestEnglish
A thick, warm forest where it rains almost every day and the trees grow very tall.
Grade 1 Geography: Maps and Journeys, Lesson 7.3 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.4 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5)
A thick, warm forest where it rains almost every day and the trees grow very tall.
Grade 1 Geography: Maps and Journeys, Lesson 7.3 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.4 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5)
raised (hanging) riverEnglish
A river whose bed has been built up by silt until it flows higher than the plain outside its dikes.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.4 (grade 8)
A river whose bed has been built up by silt until it flows higher than the plain outside its dikes.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.4 (grade 8)
rammed earthEnglish
A building method in which damp earth is pounded hard in layers between wooden boards; most early Chinese walls were built this way.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
A building method in which damp earth is pounded hard in layers between wooden boards; most early Chinese walls were built this way.
Geography and History: Why Borders Fall Where They Do, Lesson 4.5 (grade 9–12)
rank-size ruleEnglish
The pattern in which a country’s nth-largest city has about 1/n the population of the largest city.
Human Geography, Lesson 10.3 (grade 9–12) · Human Geography, Lesson 7.1 (grade 9–12)
The pattern in which a country’s nth-largest city has about 1/n the population of the largest city.
Human Geography, Lesson 10.3 (grade 9–12) · Human Geography, Lesson 7.1 (grade 9–12)
rapidEnglish
A place where a river runs fast and rough over rocks.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.2 (grade 4)
A place where a river runs fast and rough over rocks.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.2 (grade 4)
rare-earth elementsEnglish
Seventeen metals (the fifteen lanthanides plus scandium and yttrium) used in strong magnets, screens and catalysts; they are not truly rare but are scattered and very hard to separate.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
Seventeen metals (the fifteen lanthanides plus scandium and yttrium) used in strong magnets, screens and catalysts; they are not truly rare but are scattered and very hard to separate.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
rasputitsaEnglish
Russian for the “season of bad roads”: the weeks of spring thaw and autumn rain when unpaved roads and fields turn to deep mud.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
Russian for the “season of bad roads”: the weeks of spring thaw and autumn rain when unpaved roads and fields turn to deep mud.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
rate of natural increase (RNI)English
The percentage by which a population grows in a year from births minus deaths, not counting migration: RNI = (CBR − CDR) ÷ 10.
Human Geography, Lesson 2.2 (grade 9–12)
The percentage by which a population grows in a year from births minus deaths, not counting migration: RNI = (CBR − CDR) ÷ 10.
Human Geography, Lesson 2.2 (grade 9–12)
raw materialEnglish
A natural resource used to make something else, like iron ore for steel or cotton for cloth.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4)
A natural resource used to make something else, like iron ore for steel or cotton for cloth.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.3 (grade 4)
Réaumur scaleEnglish
An old temperature scale on which water freezes at 0° and boils at 80°. To convert to Celsius, multiply by 1.25.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
An old temperature scale on which water freezes at 0° and boils at 80°. To convert to Celsius, multiply by 1.25.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
receiverEnglish
A device, such as a phone or car navigation unit, that listens to satellite signals. It only listens; it sends nothing to the satellites.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8)
A device, such as a phone or car navigation unit, that listens to satellite signals. It only listens; it sends nothing to the satellites.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8)
recurrence intervalEnglish
The average number of years between events of a given size; a “100-year flood” has a 1 percent chance of happening in any one year.
Human Geography, Lesson 9.4 (grade 9–12)
The average number of years between events of a given size; a “100-year flood” has a 1 percent chance of happening in any one year.
Human Geography, Lesson 9.4 (grade 9–12)
reeferEnglish
A refrigerated container with its own cooling unit, plugged into electric power on ship and in the yard.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
A refrigerated container with its own cooling unit, plugged into electric power on ship and in the yard.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
reg and hamadaEnglish
The Sahara’s commonest surfaces: reg is a flat plain of gravel and pebbles; hamada is a bare, rocky plateau swept clean of sand by the wind.
Geography and History: Why Borders Fall Where They Do, Lesson 4.1 (grade 9–12)
The Sahara’s commonest surfaces: reg is a flat plain of gravel and pebbles; hamada is a bare, rocky plateau swept clean of sand by the wind.
Geography and History: Why Borders Fall Where They Do, Lesson 4.1 (grade 9–12)
regionEnglish
An area of the earth that a geographer treats as one unit because it shares some feature or is tied together by some connection. Regions are real, but their edges are drawn by people for a purpose.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.1 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.1 (grade 4) · +2 more
An area of the earth that a geographer treats as one unit because it shares some feature or is tied together by some connection. Regions are real, but their edges are drawn by people for a purpose.
Geopolitics: The Great Ideas, Lesson 5.1 (grade 9–12) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.1 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.1 (grade 4) · +2 more
registration marksEnglish
Holes or marks that line up from layer to layer, so each slice is traced in exactly the right place.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6)
Holes or marks that line up from layer to layer, so each slice is traced in exactly the right place.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6)
relative locationEnglish
Where a place lies compared with other places: its neighbors, its coasts and the routes that pass it. Often more important than its latitude and longitude.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12)
Where a place lies compared with other places: its neighbors, its coasts and the routes that pass it. Often more important than its latitude and longitude.
Geopolitics: The Great Ideas, Lesson 1.1 (grade 9–12)
relic boundaryEnglish
A boundary that no longer functions but can still be seen in the landscape, such as the remains of the Berlin Wall.
Human Geography, Lesson 5.2 (grade 9–12)
A boundary that no longer functions but can still be seen in the landscape, such as the remains of the Berlin Wall.
Human Geography, Lesson 5.2 (grade 9–12)
relief mapEnglish
A map that shows the height of the land, either with shading and colors or with raised bumps you can touch.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.4 (grade 4)
A map that shows the height of the land, either with shading and colors or with raised bumps you can touch.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.4 (grade 4)
religiously unaffiliatedEnglish
Survey term for people who do not identify with any religion. It includes atheists and agnostics but also many who believe in God without belonging to a religious body.
Human Geography, Lesson 4.3 (grade 9–12)
Survey term for people who do not identify with any religion. It includes atheists and agnostics but also many who believe in God without belonging to a religious body.
Human Geography, Lesson 4.3 (grade 9–12)
relocation diffusionEnglish
The spread of an idea or practice when the people who carry it move to a new place.
Human Geography, Lesson 1.2 (grade 9–12) · Human Geography, Lesson 4.2 (grade 9–12)
The spread of an idea or practice when the people who carry it move to a new place.
Human Geography, Lesson 1.2 (grade 9–12) · Human Geography, Lesson 4.2 (grade 9–12)
remittanceEnglish
Money a migrant sends home to family in the country of origin.
Human Geography, Lesson 3.2 (grade 9–12)
Money a migrant sends home to family in the country of origin.
Human Geography, Lesson 3.2 (grade 9–12)
renewable resourceEnglish
A resource that can grow back or be replaced if people care for it, such as trees, fish and crops.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.3 (grade 4) · Human Geography, Lesson 9.1 (grade 9–12)
A resource that can grow back or be replaced if people care for it, such as trees, fish and crops.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.3 (grade 4) · Human Geography, Lesson 9.1 (grade 9–12)
repeater (amplifier)English
A sealed device spliced into an undersea cable every 50 to 100 km or so to strengthen the fading light signal.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
A sealed device spliced into an undersea cable every 50 to 100 km or so to strengthen the fading light signal.
Technology Overcoming Geography, Lesson 5.3 (grade 9–12)
representative fraction (RF)English
A map scale written as a ratio, such as 1:10,000,000, meaning one unit on the map equals ten million of the same units on the ground.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12)
A map scale written as a ratio, such as 1:10,000,000, meaning one unit on the map equals ten million of the same units on the ground.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12)
research stationEnglish
A base where scientists live and work for a season or a year to study a place.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.4 (grade 3)
A base where scientists live and work for a season or a year to study a place.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.4 (grade 3)
reserves-to-production ratio (R/P)English
Proved reserves divided by the amount produced in one year; how many years current reserves would last at the current rate of production.
Human Geography, Lesson 9.1 (grade 9–12)
Proved reserves divided by the amount produced in one year; how many years current reserves would last at the current rate of production.
Human Geography, Lesson 9.1 (grade 9–12)
resource concentrationEnglish
When most of the world’s supply of a resource, or of its processing, comes from one or a few places, so that trouble in one place affects buyers everywhere.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
When most of the world’s supply of a resource, or of its processing, comes from one or a few places, so that trouble in one place affects buyers everywhere.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.5 (grade 9–12)
retrieval practiceEnglish
Studying by trying to recall information from memory (flash cards, practice questions) rather than rereading it; one of the best-tested ways to remember.
Human Geography, Lesson 10.3 (grade 9–12)
Studying by trying to recall information from memory (flash cards, practice questions) rather than rereading it; one of the best-tested ways to remember.
Human Geography, Lesson 10.3 (grade 9–12)
reversing station (zigzag)English
A place where a train runs into a dead-end siding and then backs up a second slope, climbing the hillside in a Z shape without needing to turn around.
Grade 7 Geography: Regions of the World, Lesson 5.3 (grade 7)
A place where a train runs into a dead-end siding and then backs up a second slope, climbing the hillside in a Z shape without needing to turn around.
Grade 7 Geography: Regions of the World, Lesson 5.3 (grade 7)
RhinelandEnglish
The German lands along the middle and lower Rhine, especially the left bank, around Cologne, Bonn, Koblenz and Mainz.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
The German lands along the middle and lower Rhine, especially the left bank, around Cologne, Bonn, Koblenz and Mainz.
Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12)
rhumb linesEnglish
Straight lines drawn out from a compass rose across an old sea chart, so a pilot could lay a ruler along a steady compass course.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.3 (grade 5)
Straight lines drawn out from a compass rose across an old sea chart, so a pilot could lay a ruler along a steady compass course.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.3 (grade 5)
riaEnglish
A drowned river valley: a branching inlet formed where the sea has flooded a river’s valley, such as Port Jackson at Sydney.
Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
A drowned river valley: a branching inlet formed where the sea has flooded a river’s valley, such as Port Jackson at Sydney.
Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
Ridge and ValleyEnglish
The part of the Appalachians made of long, parallel ridges separated by long valleys, running from southwest to northeast.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
The part of the Appalachians made of long, parallel ridges separated by long valleys, running from southwest to northeast.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
rift valleyEnglish
A long, deep valley made where the land has pulled apart and the middle has sunk down.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.4 (grade 3) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 3.3 (grade 7)
A long, deep valley made where the land has pulled apart and the middle has sunk down.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.4 (grade 3) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 3.3 (grade 7)
right of depositEnglish
Permission to unload goods at a port and store them, without paying duty, until they are loaded onto ocean ships. Spain granted Americans this right at New Orleans in Pinckney’s Treaty of 1795.
Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12)
Permission to unload goods at a port and store them, without paying duty, until they are loaded onto ocean ships. Spain granted Americans this right at New Orleans in Pinckney’s Treaty of 1795.
Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12)
RihlaEnglish
Arabic for “journey.” It is the name of the book that tells Ibn Battuta’s travels.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.4 (grade 3)
Arabic for “journey.” It is the name of the book that tells Ibn Battuta’s travels.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 7.4 (grade 3)
rimlandEnglish
Spykman’s name for the wide belt of lands between the Heartland and the oceans: coastal Europe, the Middle East, India, Southeast Asia and China. Mackinder had called it the inner or marginal crescent.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.3 (grade 9–12)
Spykman’s name for the wide belt of lands between the Heartland and the oceans: coastal Europe, the Middle East, India, Southeast Asia and China. Mackinder had called it the inner or marginal crescent.
Geopolitics: The Great Ideas, Lesson 4.1 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 5.3 (grade 9–12)
risk theoryEnglish
Admiral Alfred von Tirpitz’s idea that Germany needed a fleet only strong enough that Britain could not fight it without risking losses that would leave it weaker than other naval powers.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
Admiral Alfred von Tirpitz’s idea that Germany needed a fleet only strong enough that Britain could not fight it without risking losses that would leave it weaker than other naval powers.
Geopolitics: The Great Ideas, Lesson 2.3 (grade 9–12)
river basinEnglish
All the land whose rain and melted snow drain into one river and its tributaries.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.2 (grade 3)
All the land whose rain and melted snow drain into one river and its tributaries.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.2 (grade 3)
river borderEnglish
A border that follows a river. You can see it, because the river is really there.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.3 (grade 2)
A border that follows a river. You can see it, because the river is really there.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.3 (grade 2)
river crossingEnglish
A place where travelers get wagons and animals from one side of a river to the other.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.4 (grade 2)
A place where travelers get wagons and animals from one side of a river to the other.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.4 (grade 2)
river mouthEnglish
The place where a river flows into a bay, lake or the sea.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.2 (grade 4)
The place where a river flows into a bay, lake or the sea.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.2 (grade 4)
river pilotEnglish
The expert who steered a steamboat and had to know every bend, sandbar and snag of the river by heart.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
The expert who steered a steamboat and had to know every bend, sandbar and snag of the river by heart.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
river stageEnglish
The height of the water surface read on a river gauge. The highest stage of a flood is its crest.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.2 (grade 6)
The height of the water surface read on a river gauge. The highest stage of a flood is its crest.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.2 (grade 6)
river systemEnglish
A big river and all the rivers and streams that flow into it, like a tree with its branches.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.2 (grade 2)
A big river and all the rivers and streams that flow into it, like a tree with its branches.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 3.2 (grade 2)
road distanceEnglish
How far you really drive along the roads. It is usually longer than the straight-line distance because roads curve and turn.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.3 (grade 4)
How far you really drive along the roads. It is usually longer than the straight-line distance because roads curve and turn.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.3 (grade 4)
road mapEnglish
A map that shows roads and towns so travelers can find their way.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.2 (grade 2)
A map that shows roads and towns so travelers can find their way.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.2 (grade 2)
Roman mile (mille passus)English
A thousand paces, each pace (a double step) being 5 Roman feet. It is about 1,480 m, or about 0.92 of a modern mile.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
A thousand paces, each pace (a double step) being 5 Roman feet. It is about 1,480 m, or about 0.92 of a modern mile.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12)
room mapEnglish
A drawing of a room from above, as if the roof were lifted off.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.2 (grade K)
A drawing of a room from above, as if the roof were lifted off.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.2 (grade K)
Roosevelt CorollaryEnglish
Theodore Roosevelt’s addition of 1904: that the United States might act as an international police power in the hemisphere to prevent European intervention, which was later used to justify many interventions.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
Theodore Roosevelt’s addition of 1904: that the United States might act as an international police power in the hemisphere to prevent European intervention, which was later used to justify many interventions.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
route centerEnglish
A place where several roads or waterways meet, so that travelers from many directions pass through it. Geographers also call it a nodal point.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)
A place where several roads or waterways meet, so that travelers from many directions pass through it. Geographers also call it a nodal point.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)
route choiceEnglish
The path a runner picks for a leg: straight through, around an obstacle, or along a trail. Good orienteers compare distance, ground and risk.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
The path a runner picks for a leg: straight through, around an obstacle, or along a trail. Good orienteers compare distance, ground and risk.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 9.1 (grade 8)
Royal SocietyEnglish
Britain’s society of scientists, founded in 1660. It asked the king and the Navy to send Cook to the Pacific.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.1 (grade 5)
Britain’s society of scientists, founded in 1660. It asked the king and the Navy to send Cook to the Pacific.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.1 (grade 5)
Rub’ al KhaliEnglish
“The Empty Quarter,” the great sand desert of southern Arabia and the largest continuous body of sand on earth.
Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
“The Empty Quarter,” the great sand desert of southern Arabia and the largest continuous body of sand on earth.
Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
rule of V’sEnglish
Where contour lines cross a stream they bend into V’s that point upstream, the opposite way from the water’s flow.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.2 (grade 6)
Where contour lines cross a stream they bend into V’s that point upstream, the opposite way from the water’s flow.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.2 (grade 6)
running surveyEnglish
Charting a coast from a moving ship by taking bearings to headlands and hills from one spot after another along the way.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.2 (grade 5)
Charting a coast from a moving ship by taking bearings to headlands and hills from one spot after another along the way.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.2 (grade 5)
Russian gauge (broad gauge)English
5 feet (1,524 mm), chosen for the St. Petersburg–Moscow railway in the 1840s; redefined as 1,520 mm by Soviet railways from 1970. Used in Russia, Belarus, Ukraine, the Baltic states, Central Asia, Mongolia and (at 1,524 mm) Finland.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
5 feet (1,524 mm), chosen for the St. Petersburg–Moscow railway in the 1840s; redefined as 1,520 mm by Soviet railways from 1970. Used in Russia, Belarus, Ukraine, the Baltic states, Central Asia, Mongolia and (at 1,524 mm) Finland.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
S
sacred spaceEnglish
A place set apart and given special religious meaning by a faith community, such as a temple site, a tomb, a river or a mountain.
Human Geography, Lesson 4.4 (grade 9–12)
A place set apart and given special religious meaning by a faith community, such as a temple site, a tomb, a river or a mountain.
Human Geography, Lesson 4.4 (grade 9–12)
saddleEnglish
A low dip on a ridge between two higher points, shown by contour lines shaped like an hourglass.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.2 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.1 (grade 6)
A low dip on a ridge between two higher points, shown by contour lines shaped like an hourglass.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.2 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.1 (grade 6)
Saffir–Simpson scaleEnglish
A scale that ranks hurricanes from Category 1 to Category 5 by their sustained wind speed.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.3 (grade 6)
A scale that ranks hurricanes from Category 1 to Category 5 by their sustained wind speed.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.3 (grade 6)
SahelEnglish
The belt of dry grassland and thorn scrub along the southern edge of the Sahara, from Senegal to Sudan. Its name comes from an Arabic word for “shore”: the shore of the desert.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 4.1 (grade 9–12)
The belt of dry grassland and thorn scrub along the southern edge of the Sahara, from Senegal to Sudan. Its name comes from an Arabic word for “shore”: the shore of the desert.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 4.1 (grade 9–12)
sailing seasonEnglish
The months when sailing was considered safe in ancient times, roughly late spring to early autumn; in winter most shipping stopped.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
The months when sailing was considered safe in ancient times, roughly late spring to early autumn; in winter most shipping stopped.
Geography and History: Why Borders Fall Where They Do, Lesson 5.3 (grade 9–12)
salinizationEnglish
The slow buildup of salt in soil when irrigation water evaporates in a hot, dry climate and leaves its salt behind.
Grade 7 Geography: Regions of the World, Lesson 3.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.2 (grade 8)
The slow buildup of salt in soil when irrigation water evaporates in a hot, dry climate and leaves its salt behind.
Grade 7 Geography: Regions of the World, Lesson 3.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.2 (grade 8)
saltern (salt pan)English
A wide, shallow pond where seawater or brine is left in the sun and wind to evaporate, leaving salt behind.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
A wide, shallow pond where seawater or brine is left in the sun and wind to evaporate, leaving salt behind.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.1 (grade 9–12)
Sanborn mapEnglish
A large-scale map made for fire insurance companies that shows each building’s outline, size, building material and use. The Sanborn company mapped American towns from 1867 well into the twentieth century.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
A large-scale map made for fire insurance companies that shows each building’s outline, size, building material and use. The Sanborn company mapped American towns from 1867 well into the twentieth century.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
sand glassEnglish
An hourglass that measures a set time, such as half an hour, or a short glass of about half a minute for the chip log.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
An hourglass that measures a set time, such as half an hour, or a short glass of about half a minute for the chip log.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
satelliteEnglish
An object that orbits a planet. GPS satellites circle Earth about 20,200 km (12,550 miles) up, each going around twice a day.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8) · Technology Overcoming Geography, Lesson 5.1 (grade 9–12)
An object that orbits a planet. GPS satellites circle Earth about 20,200 km (12,550 miles) up, each going around twice a day.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8) · Technology Overcoming Geography, Lesson 5.1 (grade 9–12)
sauerkrautEnglish
Cabbage sliced fine and preserved in salt, where it slowly turns sour. It keeps for months in a barrel.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.3 (grade 5) · Grade 3 Physical Education & Health, Lesson 3.1 (grade 3)
Cabbage sliced fine and preserved in salt, where it slowly turns sour. It keeps for months in a barrel.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.3 (grade 5) · Grade 3 Physical Education & Health, Lesson 3.1 (grade 3)
scale 1:24,000English
One unit on the map stands for 24,000 of the same units on the ground: 1 inch = 2,000 feet, and 1 cm = 240 m.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.2 (grade 6)
One unit on the map stands for 24,000 of the same units on the ground: 1 inch = 2,000 feet, and 1 cm = 240 m.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.2 (grade 6)
scale of analysisEnglish
The level at which a geographer gathers and studies data: local, regional, national or global. Different scales can show different patterns of the same thing.
Human Geography, Lesson 1.4 (grade 9–12) · Human Geography, Lesson 10.2 (grade 9–12)
The level at which a geographer gathers and studies data: local, regional, national or global. Different scales can show different patterns of the same thing.
Human Geography, Lesson 1.4 (grade 9–12) · Human Geography, Lesson 10.2 (grade 9–12)
scorched earthEnglish
Destroying crops, stores, shelter and transport in the path of an enemy so that he cannot live off the land.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
Destroying crops, stores, shelter and transport in the path of an enemy so that he cannot live off the land.
Geography and History: Why Borders Fall Where They Do, Lesson 7.3 (grade 9–12)
Scramble for AfricaEnglish
The rapid division of nearly all of Africa among European powers between about 1880 and 1914.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
The rapid division of nearly all of Africa among European powers between about 1880 and 1914.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
seaEnglish
A large body of salt water, smaller than an ocean and often partly surrounded by land.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.1 (grade 3) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.3 (grade 3) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.3 (grade K)
A large body of salt water, smaller than an ocean and often partly surrounded by land.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.1 (grade 3) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.3 (grade 3) · Kindergarten Geography: God Made the Earth: My First Maps, Lesson 4.3 (grade K)
sea denialEnglish
Preventing an enemy from using the sea without being able to use it fully yourself, as submarines, mines and land-based aircraft can do.
Geopolitics: The Great Ideas, Lesson 2.5 (grade 9–12)
Preventing an enemy from using the sea without being able to use it fully yourself, as submarines, mines and land-based aircraft can do.
Geopolitics: The Great Ideas, Lesson 2.5 (grade 9–12)
sea iceEnglish
Frozen ocean water. Arctic sea ice is several feet thick, cracks open and drifts with the wind and currents.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.1 (grade 5) · Grade 1 Life Science: Animal Homes and Habits, Lesson 5.1 (grade 1)
Frozen ocean water. Arctic sea ice is several feet thick, cracks open and drifts with the wind and currents.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.1 (grade 5) · Grade 1 Life Science: Animal Homes and Habits, Lesson 5.1 (grade 1)
sea levelEnglish
The height of the top of the ocean. We measure how high or low land is from there.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.1 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.1 (grade 4)
The height of the top of the ocean. We measure how high or low land is from there.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.1 (grade 2) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.1 (grade 4)
sea powerEnglish
Strength that rests on fleets, sea trade, harbors and the ability to move and strike by water.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 5.4 (grade 9–12) · +1 more
Strength that rests on fleets, sea trade, harbors and the ability to move and strike by water.
Geopolitics: The Great Ideas, Lesson 1.2 (grade 9–12) · Geopolitics: The Great Ideas, Lesson 2.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 5.4 (grade 9–12) · +1 more
sea-floor spreadingEnglish
The process by which melted rock rises at a mid-ocean ridge, cools into new crust and moves away on both sides.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6)
The process by which melted rock rises at a mid-ocean ridge, cools into new crust and moves away on both sides.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.4 (grade 6)
sea-level canalEnglish
A canal with no locks, whose water stands at the level of the seas at both ends. The Suez Canal is a sea-level canal.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.2 (grade 8) · Technology Overcoming Geography, Lesson 3.1 (grade 9–12)
A canal with no locks, whose water stands at the level of the seas at both ends. The Suez Canal is a sea-level canal.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.4 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.2 (grade 8) · Technology Overcoming Geography, Lesson 3.1 (grade 9–12)
seamanshipEnglish
The skill of handling a ship and crew: reading the wind and weather, steering, and keeping everyone alive.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.1 (grade 5)
The skill of handling a ship and crew: reading the wind and weather, steering, and keeping everyone alive.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.1 (grade 5)
seawallEnglish
A strong wall built along the shore to stop waves and storm surge from washing over the land behind it.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.3 (grade 6)
A strong wall built along the shore to stop waves and storm surge from washing over the land behind it.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.3 (grade 6)
seawayEnglish
A deep-water route, made of rivers, lakes, canals and locks, that lets ocean-going ships travel far inland.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
A deep-water route, made of rivers, lakes, canals and locks, that lets ocean-going ships travel far inland.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
SeawaymaxEnglish
The largest ship that fits the Seaway locks: about 225.5 m (740 ft) long and 23.8 m (78 ft) wide.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
The largest ship that fits the Seaway locks: about 225.5 m (740 ft) long and 23.8 m (78 ft) wide.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.4 (grade 8)
second agricultural revolutionEnglish
The improvement and mechanization of farming that began in Britain in the 1700s alongside the Industrial Revolution: seed drills, crop rotation, selective breeding, enclosure, and later steel plows, reapers and tractors.
Human Geography, Lesson 6.3 (grade 9–12)
The improvement and mechanization of farming that began in Britain in the 1700s alongside the Industrial Revolution: seed drills, crop rotation, selective breeding, enclosure, and later steel plows, reapers and tractors.
Human Geography, Lesson 6.3 (grade 9–12)
Second Punic WarEnglish
The war between Rome and Carthage from 218 to 201 B.C., which began with Hannibal’s march from Spain over the Alps into Italy.
Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12)
The war between Rome and Carthage from 218 to 201 B.C., which began with Hannibal’s march from Spain over the Alps into Italy.
Geography and History: Why Borders Fall Where They Do, Lesson 3.2 (grade 9–12)
sector claimEnglish
A claim to a wedge of Antarctica bounded by two meridians, running from the coast (or from 60°S) to the South Pole.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
A claim to a wedge of Antarctica bounded by two meridians, running from the coast (or from 60°S) to the South Pole.
Geography and History: Why Borders Fall Where They Do, Lesson 9.5 (grade 9–12)
sector modelEnglish
Homer Hoyt’s model (1939) in which land uses, especially high-rent housing, form wedges that grow outward from the CBD along transportation lines and attractive land.
Human Geography, Lesson 7.3 (grade 9–12)
Homer Hoyt’s model (1939) in which land uses, especially high-rent housing, form wedges that grow outward from the CBD along transportation lines and attractive land.
Human Geography, Lesson 7.3 (grade 9–12)
seedtimeEnglish
The time, mostly in spring, when farmers plant seeds in the ground.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.2 (grade K)
The time, mostly in spring, when farmers plant seeds in the ground.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 5.2 (grade K)
semi-aridEnglish
Rather dry: getting more rain than a desert but not enough for trees and many crops, often less than about 20 inches a year.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.3 (grade 4)
Rather dry: getting more rain than a desert but not enough for trees and many crops, often less than about 20 inches a year.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.3 (grade 4)
SeramporeEnglish
A Danish trading town on the Hooghly River, about 20 km (12 mi) north of Calcutta, where Carey and his colleagues built their mission, press and college.
Grade 7 Geography: Regions of the World, Lesson 5.4 (grade 7)
A Danish trading town on the Hooghly River, about 20 km (12 mi) north of Calcutta, where Carey and his colleagues built their mission, press and college.
Grade 7 Geography: Regions of the World, Lesson 5.4 (grade 7)
sericultureEnglish
The raising of silkworms (the caterpillars of the moth Bombyx mori) on mulberry leaves and the unwinding of their cocoons into silk thread.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12) · Fabrics & Sewing II, Lesson 1.3 (grade 6–8) · Textile Science & Clothing Construction, Lesson 2.5 (grade 9–12)
The raising of silkworms (the caterpillars of the moth Bombyx mori) on mulberry leaves and the unwinding of their cocoons into silk thread.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12) · Fabrics & Sewing II, Lesson 1.3 (grade 6–8) · Textile Science & Clothing Construction, Lesson 2.5 (grade 9–12)
setting the mapEnglish
Turning the map so that north on the map points to north on the ground and every feature on the map lines up with the real one.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8)
Turning the map so that north on the map points to north on the ground and every feature on the map lines up with the real one.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.2 (grade 8)
sex ratioEnglish
The number of males for every 100 females in a population or age group. At birth it is naturally about 105.
Human Geography, Lesson 2.4 (grade 9–12)
The number of males for every 100 females in a population or age group. At birth it is naturally about 105.
Human Geography, Lesson 2.4 (grade 9–12)
sextantEnglish
A navigator’s instrument for measuring the angle of the sun or a star above the horizon, used to find latitude and, with an accurate clock, longitude.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
A navigator’s instrument for measuring the angle of the sun or a star above the horizon, used to find latitude and, with an accurate clock, longitude.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.3 (grade 5)
shadufEnglish
A water lever: a long pole on a pivot with a bucket on one end and a counterweight on the other, used to lift water from a river or canal.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.1 (grade 8)
A water lever: a long pole on a pivot with a bucket on one end and a counterweight on the other, used to lift water from a river or canal.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 2.1 (grade 8)
shatterbeltEnglish
Saul Cohen’s term (1963) for a large region of many small, divided states caught between the interests of great powers, such as the Middle East and Southeast Asia in his day.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
Saul Cohen’s term (1963) for a large region of many small, divided states caught between the interests of great powers, such as the Middle East and Southeast Asia in his day.
Geopolitics: The Great Ideas, Lesson 4.5 (grade 9–12)
shelteredEnglish
Protected from wind and waves, often by islands or by land around a bay.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.2 (grade 4)
Protected from wind and waves, often by islands or by land around a bay.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.2 (grade 4)
shifting cultivationEnglish
Clearing a patch of tropical forest (often by slash and burn), farming it for a few years, then leaving it to regrow while clearing a new patch.
Human Geography, Lesson 6.4 (grade 9–12)
Clearing a patch of tropical forest (often by slash and burn), farming it for a few years, then leaving it to regrow while clearing a new patch.
Human Geography, Lesson 6.4 (grade 9–12)
shipEnglish
A very big boat that can sail across the ocean.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 8.2 (grade K)
A very big boat that can sail across the ocean.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 8.2 (grade K)
ship manifestEnglish
The passenger list a steamship company prepared at the port of departure, recording each passenger’s name, age, origin, destination and other details for inspectors at the port of arrival.
Human Geography, Lesson 3.2 (grade 9–12)
The passenger list a steamship company prepared at the port of departure, recording each passenger’s name, age, origin, destination and other details for inspectors at the port of arrival.
Human Geography, Lesson 3.2 (grade 9–12)
ship-to-shore craneEnglish
A tall gantry crane on rails along the quay whose boom reaches out over a ship to lift containers on and off (also called an STS crane).
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
A tall gantry crane on rails along the quay whose boom reaches out over a ship to lift containers on and off (also called an STS crane).
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
shogunEnglish
The military ruler of Japan who governed in the name of the emperor; the Kamakura shogunate faced the Mongols, and the Tokugawa shogunate ruled from 1603 to 1867.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
The military ruler of Japan who governed in the name of the emperor; the Kamakura shogunate faced the Mongols, and the Tokugawa shogunate ruled from 1603 to 1867.
Geography and History: Why Borders Fall Where They Do, Lesson 5.2 (grade 9–12)
SiberiaEnglish
The huge Asian part of Russia east of the Urals, stretching to the Pacific; about three-quarters of Russia’s land.
Grade 7 Geography: Regions of the World, Lesson 2.1 (grade 7)
The huge Asian part of Russia east of the Urals, stretching to the Pacific; about three-quarters of Russia’s land.
Grade 7 Geography: Regions of the World, Lesson 2.1 (grade 7)
side viewEnglish
How something looks when you stand or sit beside it.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.1 (grade K)
How something looks when you stand or sit beside it.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.1 (grade K)
signpostingEnglish
Telling the audience where the talk is going (“First the ground, then three views, then my judgment”), so they can follow without notes.
Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12)
Telling the audience where the talk is going (“First the ground, then three views, then my judgment”), so they can follow without notes.
Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12)
sillEnglish
A raised ridge on the sea floor across a strait that limits how deep water can flow between two seas. The Camarinal Sill lies across the Strait of Gibraltar.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.2 (grade 8)
A raised ridge on the sea floor across a strait that limits how deep water can flow between two seas. The Camarinal Sill lies across the Strait of Gibraltar.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.2 (grade 8)
single trackEnglish
A railway with one line of rails, on which trains going in opposite directions must wait for each other at passing sidings, which limits how many trains can run.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7)
A railway with one line of rails, on which trains going in opposite directions must wait for each other at passing sidings, which limits how many trains can run.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7)
Sino-Soviet splitEnglish
The break between Communist China and the Soviet Union that grew from the late 1950s into open hostility in the 1960s.
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
The break between Communist China and the Soviet Union that grew from the late 1950s into open hostility in the 1960s.
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
sinuosityEnglish
How much a river winds: the channel length divided by the straight-line distance between its ends.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.4 (grade 6)
How much a river winds: the channel length divided by the straight-line distance between its ends.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.4 (grade 6)
siteEnglish
The physical character of a place itself: depth of water, shelter, firm land, tides.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.4 (grade 3) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8) · +3 more
The physical character of a place itself: depth of water, shelter, firm land, tides.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 2.4 (grade 3) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8) · +3 more
situationEnglish
A place’s location relative to other places: sea lanes, rivers, markets, resources and the hinterland.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.1 (grade 8) · +2 more
A place’s location relative to other places: sea lanes, rivers, markets, resources and the hinterland.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.1 (grade 8) · +2 more
sliding (transform) boundaryEnglish
A plate edge where two plates grind sideways past each other, as along the San Andreas Fault in California.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.2 (grade 6)
A plate edge where two plates grind sideways past each other, as along the San Andreas Fault in California.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.2 (grade 6)
sluiceEnglish
An opening or valve that lets water flow into or out of a lock chamber.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7)
An opening or valve that lets water flow into or out of a lock chamber.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7)
snagEnglish
A sunken tree stuck in the river bottom that could rip a hole in a boat’s hull.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
A sunken tree stuck in the river bottom that could rip a hole in a boat’s hull.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 6.4 (grade 4)
snowshedEnglish
A long wooden roof built over a railroad track in the mountains so that snow and avalanches slide over the trains instead of burying the line.
Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12)
A long wooden roof built over a railroad track in the mountains so that snow and avalanches slide over the trains instead of burying the line.
Geography and History: Why Borders Fall Where They Do, Lesson 8.4 (grade 9–12)
sod houseEnglish
A house with walls built of bricks of sod, also called a “soddy.”
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.4 (grade 4)
A house with walls built of bricks of sod, also called a “soddy.”
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 3.4 (grade 4)
SogdiansEnglish
An Iranian people of the region around Samarkand and Bukhara who were the leading long-distance merchants of the Silk Road from about A.D. 300 to 800.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12)
An Iranian people of the region around Samarkand and Bukhara who were the leading long-distance merchants of the Silk Road from about A.D. 300 to 800.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12)
Sound DuesEnglish
Tolls that Denmark charged ships passing the Øresund strait into and out of the Baltic for about four centuries, until 1857.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
Tolls that Denmark charged ships passing the Øresund strait into and out of the Baltic for about four centuries, until 1857.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
soundingEnglish
Measuring the depth of the water by dropping a weighted line, the lead line, to the bottom.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.4 (grade 5)
Measuring the depth of the water by dropping a weighted line, the lead line, to the bottom.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.4 (grade 5)
southEnglish
The direction toward the South Pole. On a globe and on most maps, south is down.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 2.4 (grade K)
The direction toward the South Pole. On a globe and on most maps, south is down.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 2.4 (grade K)
South PoleEnglish
The very bottom of the earth. It sits on Antarctica, a land covered with thick ice.
Grade 1 Geography: Maps and Journeys, Lesson 5.2 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.4 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5) · +2 more
The very bottom of the earth. It sits on Antarctica, a land covered with thick ice.
Grade 1 Geography: Maps and Journeys, Lesson 5.2 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.4 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.2 (grade 5) · +2 more
southwest monsoonEnglish
The summer monsoon, about June to September: strong, moist winds from the southwest that bring heavy rain to India’s west coast and rough seas to the Arabian Sea.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
The summer monsoon, about June to September: strong, moist winds from the southwest that bring heavy rain to India’s west coast and rough seas to the Arabian Sea.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.1 (grade 9–12)
sovereigntyEnglish
Supreme authority over a territory: the right to make and enforce its laws and to deal with other states. Historical atlases mostly map sovereignty and its changes.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12) · Human Geography, Lesson 5.1 (grade 9–12)
Supreme authority over a territory: the right to make and enforce its laws and to deal with other states. Historical atlases mostly map sovereignty and its changes.
Geography and History: Why Borders Fall Where They Do, Lesson 1.3 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.2 (grade 9–12) · Human Geography, Lesson 5.1 (grade 9–12)
spaced repetitionEnglish
Reviewing material at growing intervals (a day, a few days, a week) rather than all at once, so that it moves into long-term memory.
Human Geography, Lesson 10.3 (grade 9–12)
Reviewing material at growing intervals (a day, a few days, a week) rather than all at once, so that it moves into long-term memory.
Human Geography, Lesson 10.3 (grade 9–12)
speed over the groundEnglish
How fast a ship actually moves past the sea floor or the land, after the current is added or taken away from its speed through the water.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.1 (grade 6)
How fast a ship actually moves past the sea floor or the land, after the current is added or taken away from its speed through the water.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.1 (grade 6)
sphere of influenceEnglish
A region where one power claims special rights and excludes rivals, short of ruling it directly.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
A region where one power claims special rights and excludes rivals, short of ruling it directly.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
Spice IslandsEnglish
The Moluccas, small islands in what is now Indonesia, where cloves and nutmeg grow. Europeans paid very high prices for these spices.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.4 (grade 5) · Grade 7 Geography: Regions of the World, Lesson 7.1 (grade 7)
The Moluccas, small islands in what is now Indonesia, where cloves and nutmeg grow. Europeans paid very high prices for these spices.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 1.4 (grade 5) · Grade 7 Geography: Regions of the World, Lesson 7.1 (grade 7)
spine (core river)English
A river that runs through the heart of a country and ties its regions together, as opposed to one that runs along its edge.
Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12)
A river that runs through the heart of a country and ties its regions together, as opposed to one that runs along its edge.
Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12)
spiral (helical) tunnelEnglish
A tunnel that turns in a loop inside a mountain so a railway can gain height while keeping a gentle grade. The Gotthard line uses several.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
A tunnel that turns in a loop inside a mountain so a railway can gain height while keeping a gentle grade. The Gotthard line uses several.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
spiral tunnelEnglish
A tunnel that curls around inside a mountain so a railway can gain height in a short distance without getting too steep.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7)
A tunnel that curls around inside a mountain so a railway can gain height in a short distance without getting too steep.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7)
sponsorEnglish
A king, company or society that pays for an expedition, as Prince Henry paid for the Portuguese voyages.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.2 (grade 5)
A king, company or society that pays for an expedition, as Prince Henry paid for the Portuguese voyages.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 9.2 (grade 5)
spot heightEnglish
A single measured elevation printed on a map beside a dot or triangle.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.1 (grade 6)
A single measured elevation printed on a map beside a dot or triangle.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.1 (grade 6)
spreaderEnglish
The steel frame hanging from a container crane that drops onto a box and locks its four twistlocks into the corner fittings.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
The steel frame hanging from a container crane that drops onto a box and locks its four twistlocks into the corner fittings.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
spreading (divergent) boundaryEnglish
A plate edge where two plates move apart and melted rock rises to make new crust, as at the Mid-Atlantic Ridge.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.2 (grade 6)
A plate edge where two plates move apart and melted rock rises to make new crust, as at the Mid-Atlantic Ridge.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 2.2 (grade 6)
square sailEnglish
A four-sided sail hung crosswise on the mast. It works best when the wind blows from behind the ship.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3)
A four-sided sail hung crosswise on the mast. It works best when the wind blows from behind the ship.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3)
St. Lawrence LowlandsEnglish
The flat, fertile lands along the St. Lawrence River and the shores of Lakes Erie and Ontario, where Quebec City, Montreal and Toronto stand and most Canadians live.
Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
The flat, fertile lands along the St. Lawrence River and the shores of Lakes Erie and Ontario, where Quebec City, Montreal and Toronto stand and most Canadians live.
Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
stadion (plural stadia)English
A Greek unit of distance, originally the length of a race course, about 600 Greek feet. Its exact length varied from place to place, roughly 157 to 185 meters (515 to 607 feet).
Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
A Greek unit of distance, originally the length of a race course, about 600 Greek feet. Its exact length varied from place to place, roughly 157 to 185 meters (515 to 607 feet).
Geography and History: Why Borders Fall Where They Do, Lesson 1.1 (grade 9–12)
staircase (flight) of locksEnglish
Several locks built one right after another, so that the upper gates of one lock are the lower gates of the next, used to climb a steep slope.
Technology Overcoming Geography, Lesson 2.2 (grade 9–12)
Several locks built one right after another, so that the upper gates of one lock are the lower gates of the next, used to climb a steep slope.
Technology Overcoming Geography, Lesson 2.2 (grade 9–12)
standard gaugeEnglish
4 feet 8½ inches (1,435 mm), the gauge of George Stephenson’s early British railways, made the British standard by the Gauge Act of 1846 and now used by most of the world’s railways.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
4 feet 8½ inches (1,435 mm), the gauge of George Stephenson’s early British railways, made the British standard by the Gauge Act of 1846 and now used by most of the world’s railways.
Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
stateless nationEnglish
A nation without a state of its own, such as the Kurds, whose homeland lies across Turkey, Iraq, Iran and Syria.
Human Geography, Lesson 5.1 (grade 9–12)
A nation without a state of its own, such as the Kurds, whose homeland lies across Turkey, Iraq, Iran and Syria.
Human Geography, Lesson 5.1 (grade 9–12)
steaming rangeEnglish
How far a ship can go on a full load of fuel at a given speed. Range falls sharply at high speed, because fuel use rises much faster than speed.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12)
How far a ship can go on a full load of fuel at a given speed. Range falls sharply at high speed, because fuel use rises much faster than speed.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12)
steerageEnglish
The cheapest accommodation on a passenger ship, below decks, where most emigrants crossed the Atlantic.
Human Geography, Lesson 3.2 (grade 9–12)
The cheapest accommodation on a passenger ship, below decks, where most emigrants crossed the Atlantic.
Human Geography, Lesson 3.2 (grade 9–12)
step migrationEnglish
Migration made in stages, for example from farm to market town, then from town to a great city.
Human Geography, Lesson 3.1 (grade 9–12)
Migration made in stages, for example from farm to market town, then from town to a great city.
Human Geography, Lesson 3.1 (grade 9–12)
steppe–sown frontierEnglish
The zone where grassland used by nomads meets the farmland (“the sown”) of settled peoples; for most of history the real border of Eurasia.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
The zone where grassland used by nomads meets the farmland (“the sown”) of settled peoples; for most of history the real border of Eurasia.
Geography and History: Why Borders Fall Where They Do, Lesson 4.3 (grade 9–12)
stepping stonesEnglish
A chain of islands or bases spaced so that ships, and later aircraft, can cross a wide ocean in legs shorter than their range.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12)
A chain of islands or bases spaced so that ships, and later aircraft, can cross a wide ocean in legs shorter than their range.
Geopolitics: The Great Ideas, Lesson 2.4 (grade 9–12)
stern-post rudderEnglish
A flat blade hung on hinges (pintles and gudgeons) on the straight post at the back of a ship, on its centerline, and turned by a tiller or wheel.
Technology Overcoming Geography, Lesson 1.1 (grade 9–12)
A flat blade hung on hinges (pintles and gudgeons) on the straight post at the back of a ship, on its centerline, and turned by a tiller or wheel.
Technology Overcoming Geography, Lesson 1.1 (grade 9–12)
stick chartEnglish
A Marshall Islands teaching chart made of tied sticks and shells, showing islands and the ways swells move and bend around them.
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
A Marshall Islands teaching chart made of tied sticks and shells, showing islands and the ways swells move and bend around them.
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
stimulus setEnglish
A group of multiple-choice questions that share one map, graph, table, image or passage.
Human Geography, Lesson 10.3 (grade 9–12)
A group of multiple-choice questions that share one map, graph, table, image or passage.
Human Geography, Lesson 10.3 (grade 9–12)
stockyardEnglish
A place with many fenced pens where cattle are kept before they are loaded onto trains or sold.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4)
A place with many fenced pens where cattle are kept before they are loaded onto trains or sold.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.4 (grade 4)
stopEnglish
A place where you stay a while on a trip before going on.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.2 (grade 2) · Fabrics & Sewing II, Lesson 4.3 (grade 6–8)
A place where you stay a while on a trip before going on.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 9.2 (grade 2) · Fabrics & Sewing II, Lesson 4.3 (grade 6–8)
stop-and-go determinismEnglish
Griffith Taylor’s middle view (also called neo-determinism): nature sets the general direction, and people can speed up, slow down or stop, but not change the route.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12)
Griffith Taylor’s middle view (also called neo-determinism): nature sets the general direction, and people can speed up, slow down or stop, but not change the route.
Geopolitics: The Great Ideas, Lesson 1.3 (grade 9–12)
storm surge barrierEnglish
A dam with huge movable gates that stay open in calm weather and close when a storm surge threatens.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.1 (grade 6)
A dam with huge movable gates that stay open in calm weather and close when a storm surge threatens.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.1 (grade 6)
straddle carrierEnglish
A tall vehicle that drives over a container, lifts it from above and carries it between the quay and the stacks.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
A tall vehicle that drives over a container, lifts it from above and carries it between the quay and the stacks.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.4 (grade 8)
Strait of DoverEnglish
The narrowest part of the Channel, about 21 miles (34 km) wide, between Dover in England and Calais in France.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.4 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 5.1 (grade 9–12)
The narrowest part of the Channel, about 21 miles (34 km) wide, between Dover in England and Calais in France.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.4 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 5.1 (grade 9–12)
Strait of GibraltarEnglish
The channel, about 36 miles (58 km) long and as narrow as about 9 miles (14 km), that joins the Atlantic Ocean to the Mediterranean Sea between Spain and Morocco.
Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
The channel, about 36 miles (58 km) long and as narrow as about 9 miles (14 km), that joins the Atlantic Ocean to the Mediterranean Sea between Spain and Morocco.
Geography and History: Why Borders Fall Where They Do, Lesson 6.2 (grade 9–12)
Strait of MalaccaEnglish
The long sea passage, about 550 miles (900 km), between the Malay Peninsula and the island of Sumatra; the main sea route between the Indian Ocean and the South China Sea.
Geography and History: Why Borders Fall Where They Do, Lesson 6.3 (grade 9–12)
The long sea passage, about 550 miles (900 km), between the Malay Peninsula and the island of Sumatra; the main sea route between the Indian Ocean and the South China Sea.
Geography and History: Why Borders Fall Where They Do, Lesson 6.3 (grade 9–12)
Strait of MessinaEnglish
The narrow channel, about 3 km (2 miles) wide at its narrowest, between Sicily and the toe of Italy.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
The narrow channel, about 3 km (2 miles) wide at its narrowest, between Sicily and the toe of Italy.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
Strait of SicilyEnglish
The sea passage, about 145 km (90 miles) wide, between western Sicily and Cape Bon in Tunisia, joining the western and eastern basins of the Mediterranean.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
The sea passage, about 145 km (90 miles) wide, between western Sicily and Cape Bon in Tunisia, joining the western and eastern basins of the Mediterranean.
Geography and History: Why Borders Fall Where They Do, Lesson 5.5 (grade 9–12)
strategic depthEnglish
The distance between a country’s front line and its heart (capital, cities, industry). Great depth lets a defender retreat, trade space for time and wear an invader down.
Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.5 (grade 9–12)
The distance between a country’s front line and its heart (capital, cities, industry). Great depth lets a defender retreat, trade space for time and wear an invader down.
Geography and History: Why Borders Fall Where They Do, Lesson 7.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 8.5 (grade 9–12)
stream tableEnglish
A tilted tray of sand or soil with water running across it, used to watch rivers carve, carry and drop sediment.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.4 (grade 6)
A tilted tray of sand or soil with water running across it, used to watch rivers carve, carry and drop sediment.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.4 (grade 6)
streetEnglish
A road with houses or stores along it. Each street has a name.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.4 (grade K)
A road with houses or stores along it. Each street has a name.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.4 (grade K)
streetcar suburbEnglish
A residential district built along an electric streetcar or horsecar line in the late 1800s and early 1900s, with houses within a short walk of the tracks.
Human Geography, Lesson 7.4 (grade 9–12)
A residential district built along an electric streetcar or horsecar line in the late 1800s and early 1900s, with houses within a short walk of the tracks.
Human Geography, Lesson 7.4 (grade 9–12)
stripeEnglish
A long, thin band of color. Our flag has 13 stripes for the first 13 states.
Grade 1 Geography: Maps and Journeys, Lesson 6.4 (grade 1)
A long, thin band of color. Our flag has 13 stripes for the first 13 states.
Grade 1 Geography: Maps and Journeys, Lesson 6.4 (grade 1)
strongpoint defenseEnglish
Defending a few vital places, such as the main centers of industry, rather than every point on a frontier. Kennan favored it.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
Defending a few vital places, such as the main centers of industry, rather than every point on a frontier. Kennan favored it.
Geopolitics: The Great Ideas, Lesson 4.2 (grade 9–12)
subcontinentEnglish
A large, distinct part of a continent. The Indian subcontinent (India, Pakistan, Bangladesh, Nepal, Bhutan and Sri Lanka) is walled off from the rest of Asia by mountains.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
A large, distinct part of a continent. The Indian subcontinent (India, Pakistan, Bangladesh, Nepal, Bhutan and Sri Lanka) is walled off from the rest of Asia by mountains.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
subduction zoneEnglish
A converging plate edge where one plate dives beneath another, marked by an ocean trench, a line of volcanoes, and earthquakes both shallow and deep.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
A converging plate edge where one plate dives beneath another, marked by an ocean trench, a line of volcanoes, and earthquakes both shallow and deep.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
submersible bridgeEnglish
A bridge that sinks below the water to let ships pass over it, then rises again for traffic; there is one at each end of the Corinth Canal.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
A bridge that sinks below the water to let ships pass over it, then rises again for traffic; there is one at each end of the Corinth Canal.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
subsequent boundaryEnglish
A boundary drawn after settlement, often to follow differences of language or religion that already existed, such as the India–Pakistan border of 1947.
Human Geography, Lesson 5.2 (grade 9–12)
A boundary drawn after settlement, often to follow differences of language or religion that already existed, such as the India–Pakistan border of 1947.
Human Geography, Lesson 5.2 (grade 9–12)
subsistence agricultureEnglish
Farming mainly to feed the farmer’s own family, with little sold for cash.
Human Geography, Lesson 6.4 (grade 9–12)
Farming mainly to feed the farmer’s own family, with little sold for cash.
Human Geography, Lesson 6.4 (grade 9–12)
subtropical highEnglish
A belt of high pressure near 20° to 30° latitude where air sinks, warms and dries out, so clouds rarely form.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.2 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
A belt of high pressure near 20° to 30° latitude where air sinks, warms and dries out, so clouds rarely form.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.2 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 7.3 (grade 7)
suburban sprawlEnglish
Low-density growth spreading outward from a city, usually built around the automobile; its critics and defenders disagree about its costs and benefits.
Human Geography, Lesson 9.3 (grade 9–12)
Low-density growth spreading outward from a city, usually built around the automobile; its critics and defenders disagree about its costs and benefits.
Human Geography, Lesson 9.3 (grade 9–12)
suburbanizationEnglish
The movement of people, homes and later jobs and shopping from the central city to the surrounding communities.
Human Geography, Lesson 7.4 (grade 9–12)
The movement of people, homes and later jobs and shopping from the central city to the surrounding communities.
Human Geography, Lesson 7.4 (grade 9–12)
suggestive mapEnglish
A map drawn to persuade rather than inform, using arrows, shading and selective facts to make a political claim look like a fact of nature.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
A map drawn to persuade rather than inform, using arrows, shading and selective facts to make a political claim look like a fact of nature.
Geopolitics: The Great Ideas, Lesson 3.4 (grade 9–12)
summit levelEnglish
The highest stretch of a canal. It must be fed with fresh water, because every boat that passes through takes water down the locks on either side.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8) · Technology Overcoming Geography, Lesson 2.2 (grade 9–12)
The highest stretch of a canal. It must be fed with fresh water, because every boat that passes through takes water down the locks on either side.
Grade 7 Geography: Regions of the World, Lesson 6.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8) · Technology Overcoming Geography, Lesson 2.2 (grade 9–12)
sun time (local time)English
Time set by the sun in one place, so that noon is the moment the sun is highest in the sky there.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.3 (grade 4)
Time set by the sun in one place, so that noon is the moment the sun is highest in the sky there.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.3 (grade 4)
superimposed boundaryEnglish
A boundary imposed on an area by outside powers, with little regard for the peoples living there, such as most borders drawn in Africa after the Berlin Conference of 1884–85.
Human Geography, Lesson 5.2 (grade 9–12)
A boundary imposed on an area by outside powers, with little regard for the peoples living there, such as most borders drawn in Africa after the Berlin Conference of 1884–85.
Human Geography, Lesson 5.2 (grade 9–12)
supertanker (VLCC)English
A “very large crude carrier,” an oil tanker that carries about 2 million barrels.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.3 (grade 8)
A “very large crude carrier,” an oil tanker that carries about 2 million barrels.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.3 (grade 8)
support partyEnglish
A team that carries food and fuel ahead for the main party, breaks the trail, and then turns back.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.1 (grade 5)
A team that carries food and fuel ahead for the main party, breaks the trail, and then turns back.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 7.1 (grade 5)
supranational organizationEnglish
An association of three or more states that agree to work together and accept some shared rules or institutions above the level of a single state.
Human Geography, Lesson 5.4 (grade 9–12)
An association of three or more states that agree to work together and accept some shared rules or institutions above the level of a single state.
Human Geography, Lesson 5.4 (grade 9–12)
surveyorEnglish
A person who measures the land carefully to find exactly where a line or a place should be.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.3 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.2 (grade 3) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.1 (grade 4) · +1 more
A person who measures the land carefully to find exactly where a line or a place should be.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.3 (grade 2) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.2 (grade 3) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 1.1 (grade 4) · +1 more
suspended riverEnglish
A river whose bed has been raised by silt until it flows above the level of the land around it, held in only by its dikes. Parts of the lower Yellow River are suspended rivers.
Grade 7 Geography: Regions of the World, Lesson 6.1 (grade 7)
A river whose bed has been raised by silt until it flows above the level of the land around it, held in only by its dikes. Parts of the lower Yellow River are suspended rivers.
Grade 7 Geography: Regions of the World, Lesson 6.1 (grade 7)
swampEnglish
Wet, soggy land where trees grow up out of shallow water.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.2 (grade 2)
Wet, soggy land where trees grow up out of shallow water.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.2 (grade 2)
swellEnglish
A long, smooth ocean wave that rolls in steadily from the same direction, often for days.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.1 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
A long, smooth ocean wave that rolls in steadily from the same direction, often for days.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.1 (grade 3) · Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
Sykes–Picot agreementEnglish
The secret understanding concluded in May 1916 by Britain and France, with Russian assent, dividing much of the Ottoman Empire’s Arab lands into zones of direct control and influence after the war. Named for its negotiators, Sir Mark Sykes and François Georges-Picot.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
The secret understanding concluded in May 1916 by Britain and France, with Russian assent, dividing much of the Ottoman Empire’s Arab lands into zones of direct control and influence after the war. Named for its negotiators, Sir Mark Sykes and François Georges-Picot.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
synthesisEnglish
Bringing several ideas together into one judgment that keeps what is true in each and drops what fails.
Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12) · Human Geography, Lesson 10.4 (grade 9–12)
Bringing several ideas together into one judgment that keeps what is true in each and drops what fails.
Geopolitics: The Great Ideas, Lesson 5.5 (grade 9–12) · Human Geography, Lesson 10.4 (grade 9–12)
T
tackingEnglish
Zigzagging back and forth at a slant to make headway toward the wind.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3) · Technology Overcoming Geography, Lesson 1.1 (grade 9–12)
Zigzagging back and forth at a slant to make headway toward the wind.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3) · Technology Overcoming Geography, Lesson 1.1 (grade 9–12)
taigaEnglish
The great northern forest of conifers (also called the boreal forest) that crosses Alaska, Canada, Scandinavia and Russia; the largest land biome on earth.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 2.1 (grade 7)
The great northern forest of conifers (also called the boreal forest) that crosses Alaska, Canada, Scandinavia and Russia; the largest land biome on earth.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 2.1 (grade 7)
take-offEnglish
Rostow’s third stage, a period of about twenty years in which investment rises above about 10 percent of national income, leading industries grow fast and growth becomes self-sustaining.
Human Geography, Lesson 8.3 (grade 9–12)
Rostow’s third stage, a period of about twenty years in which investment rises above about 10 percent of national income, leading industries grow fast and growth becomes self-sustaining.
Human Geography, Lesson 8.3 (grade 9–12)
task verbEnglish
The command word that tells you what a free-response part requires: identify, define, describe, explain, compare, or explain the degree to which.
Human Geography, Lesson 10.1 (grade 9–12)
The command word that tells you what a free-response part requires: identify, define, describe, explain, compare, or explain the degree to which.
Human Geography, Lesson 10.1 (grade 9–12)
technology transferEnglish
The passing of a skill or invention, such as papermaking or silk-raising, from one people to another.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
The passing of a skill or invention, such as papermaking or silk-raising, from one people to another.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
tehsilEnglish
A subdivision of a district in British India (called a thana or subdivision in parts of Bengal). Census figures for tehsils were the building blocks of the boundary.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
A subdivision of a district in British India (called a thana or subdivision in parts of Bengal). Census figures for tehsils were the building blocks of the boundary.
Geography and History: Why Borders Fall Where They Do, Lesson 9.4 (grade 9–12)
Telegraph PlateauEnglish
The name the American naval officer Matthew Fontaine Maury gave to the broad, fairly even stretch of North Atlantic floor between Ireland and Newfoundland, about two miles deep, which his soundings suggested was suitable for a cable.
Technology Overcoming Geography, Lesson 4.2 (grade 9–12)
The name the American naval officer Matthew Fontaine Maury gave to the broad, fairly even stretch of North Atlantic floor between Ireland and Newfoundland, about two miles deep, which his soundings suggested was suitable for a cable.
Technology Overcoming Geography, Lesson 4.2 (grade 9–12)
temperate deciduous forestEnglish
A forest of broadleaf trees such as oak, maple, beech and hickory that drop their leaves each autumn, found where there are four seasons and rain all year.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6)
A forest of broadleaf trees such as oak, maple, beech and hickory that drop their leaves each autumn, found where there are four seasons and rain all year.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.3 (grade 6)
territorial seaEnglish
The band of sea, up to 12 nautical miles wide, that a coastal nation may claim along its shore.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.1 (grade 8)
The band of sea, up to 12 nautical miles wide, that a coastal nation may claim along its shore.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.1 (grade 8)
TEU (twenty-foot equivalent unit)English
The standard measure of container capacity: one 20-foot container. A 40-foot box counts as 2 TEU (also called an FEU).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
The standard measure of container capacity: one 20-foot container. A 40-foot box counts as 2 TEU (also called an FEU).
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
thalwegEnglish
From German Talweg, “valley way”: the line of the deepest channel of a river. Many treaties place a river border on the thalweg rather than halfway between the banks (the median line).
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
From German Talweg, “valley way”: the line of the deepest channel of a river. Many treaties place a river border on the thalweg rather than halfway between the banks (the median line).
Geography and History: Why Borders Fall Where They Do, Lesson 1.2 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 2.1 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
the AmericasEnglish
The two continents of North America and South America, joined by a narrow strip of land.
Grade 1 Geography: Maps and Journeys, Lesson 7.3 (grade 1)
The two continents of North America and South America, joined by a narrow strip of land.
Grade 1 Geography: Maps and Journeys, Lesson 7.3 (grade 1)
the last mileEnglish
The final step of delivery from a local warehouse or store to the customer’s door, often the most costly per mile.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
The final step of delivery from a local warehouse or store to the customer’s door, often the most costly per mile.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.5 (grade 9–12)
the lower 48English
The 48 states that touch each other in one big piece, from the Atlantic Ocean to the Pacific Ocean.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.1 (grade 2)
The 48 states that touch each other in one big piece, from the Atlantic Ocean to the Pacific Ocean.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.1 (grade 2)
the NarrowsEnglish
The tightest part of the Dardanelles, at Çanakkale, about three-quarters of a mile (1.2 km) wide, guarded by forts on both shores.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
The tightest part of the Dardanelles, at Çanakkale, about three-quarters of a mile (1.2 km) wide, guarded by forts on both shores.
Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)
the New WorldEnglish
The name Europeans gave to North and South America, lands that people in Europe, Africa and Asia had not known about before 1492.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.1 (grade 3)
The name Europeans gave to North and South America, lands that people in Europe, Africa and Asia had not known about before 1492.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.1 (grade 3)
thematic mapEnglish
A map made to show one subject, or theme, such as population, religion, rainfall, crops or trade, across an area.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.4 (grade 8) · Human Geography, Lesson 1.1 (grade 9–12)
A map made to show one subject, or theme, such as population, religion, rainfall, crops or trade, across an area.
Grade 7 Geography: Regions of the World, Lesson 9.1 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.4 (grade 8) · Human Geography, Lesson 1.1 (grade 9–12)
theodoliteEnglish
A telescope mounted on finely divided horizontal and vertical circles, used to measure angles between distant points and angles of elevation.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12) · Geometry, Lesson 9.7 (grade 9–10)
A telescope mounted on finely divided horizontal and vertical circles, used to measure angles between distant points and angles of elevation.
Geography and History: Why Borders Fall Where They Do, Lesson 10.3 (grade 9–12) · Geometry, Lesson 9.7 (grade 9–10)
Thomas ChristiansEnglish
The ancient churches of Kerala, which trace their founding by tradition to the apostle Thomas in the first century; Christians are recorded there by the sixth century.
Grade 7 Geography: Regions of the World, Lesson 5.4 (grade 7)
The ancient churches of Kerala, which trace their founding by tradition to the apostle Thomas in the first century; Christians are recorded there by the sixth century.
Grade 7 Geography: Regions of the World, Lesson 5.4 (grade 7)
tidal rangeEnglish
The difference in height between high tide and the low tide that follows it.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.3 (grade 6) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
The difference in height between high tide and the low tide that follows it.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.3 (grade 6) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
tidal riverEnglish
The lower part of a river where the sea’s tide rises and falls twice a day, carrying ships upstream on the flood tide and back down on the ebb.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)
The lower part of a river where the sea’s tide rises and falls twice a day, carrying ships upstream on the flood tide and back down on the ebb.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)
tide lockEnglish
A lock at the mouth of a canal whose main purpose is not to climb a hill but to keep rising and falling sea tides from running into the canal.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
A lock at the mouth of a canal whose main purpose is not to climb a hill but to keep rising and falling sea tides from running into the canal.
Technology Overcoming Geography, Lesson 3.4 (grade 9–12)
tide tableEnglish
A printed or online list of the times and heights of high and low tide for a place, worked out in advance.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.3 (grade 6)
A printed or online list of the times and heights of high and low tide for a place, worked out in advance.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.3 (grade 6)
tie pointEnglish
A feature that appears on both an old and a new map, such as a street corner, church or river bend, used to line the two maps up.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
A feature that appears on both an old and a new map, such as a street corner, church or river bend, used to line the two maps up.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
time-distanceEnglish
How long a trip takes, rather than how many miles long it is. New technology shrinks time-distance even when the miles stay the same.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.2 (grade 8)
How long a trip takes, rather than how many miles long it is. New technology shrinks time-distance even when the miles stay the same.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.2 (grade 8)
tipiEnglish
A cone-shaped tent of long wooden poles covered with bison hides. It could be taken down and moved in a short time.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.2 (grade 2)
A cone-shaped tent of long wooden poles covered with bison hides. It could be taken down and moved in a short time.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.2 (grade 2)
TODALSSEnglish
A checklist of the parts every finished map needs: Title, Orientation, Date, Author, Legend, Scale and Sources.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.4 (grade 8)
A checklist of the parts every finished map needs: Title, Orientation, Date, Author, Legend, Scale and Sources.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.4 (grade 8)
ton-kilometerEnglish
One tonne of freight moved one kilometer; a common measure for comparing transport work and cost.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
One tonne of freight moved one kilometer; a common measure for comparing transport work and cost.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
tonneEnglish
A metric ton: 1,000 kilograms, or about 2,205 pounds (about 1.1 U.S. tons). Ports measure bulk cargo in tonnes.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8)
A metric ton: 1,000 kilograms, or about 2,205 pounds (about 1.1 U.S. tons). Ports measure bulk cargo in tonnes.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.1 (grade 8)
tonne-kilometerEnglish
A measure of freight work: one metric tonne (1,000 kg) moved one kilometer. Cost per tonne-kilometer lets us compare camels, wagons, ships and trains fairly. (One tonne-km is about 0.68 ton-miles.)
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.5 (grade 9–12)
A measure of freight work: one metric tonne (1,000 kg) moved one kilometer. Cost per tonne-kilometer lets us compare camels, wagons, ships and trains fairly. (One tonne-km is about 0.68 ton-miles.)
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.5 (grade 9–12)
tornado watch / tornado warningEnglish
A watch means conditions are right for tornadoes in the next several hours: be ready. A warning means a tornado has been seen or detected by radar: take shelter now.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.4 (grade 6)
A watch means conditions are right for tornadoes in the next several hours: be ready. A warning means a tornado has been seen or detected by radar: take shelter now.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.4 (grade 6)
tornaviajeEnglish
Spanish for “return voyage”: the eastward route from the Philippines across the North Pacific to Mexico, first sailed successfully in 1565.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12) · Grade 8 Spanish, Lesson 1.1 (grade 8)
Spanish for “return voyage”: the eastward route from the Philippines across the North Pacific to Mexico, first sailed successfully in 1565.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12) · Grade 8 Spanish, Lesson 1.1 (grade 8)
total fertility rate (TFR)English
The average number of children a woman would bear over her lifetime at current birth rates. About 2.1 is replacement level in countries with low death rates.
Human Geography, Lesson 10.2 (grade 9–12) · Human Geography, Lesson 2.2 (grade 9–12) · Economics & the History of Money, Lesson 11.7 (grade 11–12)
The average number of children a woman would bear over her lifetime at current birth rates. About 2.1 is replacement level in countries with low death rates.
Human Geography, Lesson 10.2 (grade 9–12) · Human Geography, Lesson 2.2 (grade 9–12) · Economics & the History of Money, Lesson 11.7 (grade 11–12)
totem poleEnglish
A tall cedar pole carved with animals and people that tell a family’s story, like a family crest. It is not something to worship.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.4 (grade 2)
A tall cedar pole carved with animals and people that tell a family’s story, like a family crest. It is not something to worship.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.4 (grade 2)
towboat and barge towEnglish
A powerful riverboat that pushes a group of barges lashed together, the main way bulk cargo moves on the Mississippi today.
Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12)
A powerful riverboat that pushes a group of barges lashed together, the main way bulk cargo moves on the Mississippi today.
Geography and History: Why Borders Fall Where They Do, Lesson 2.5 (grade 9–12)
track gaugeEnglish
The distance between the two rails. Russian railways use a broad gauge of about 1,520 mm (just under 5 ft), wider than the 1,435 mm (4 ft 8.5 in) used in most of Europe and North America.
Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
The distance between the two rails. Russian railways use a broad gauge of about 1,520 mm (just under 5 ft), wider than the 1,435 mm (4 ft 8.5 in) used in most of Europe and North America.
Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
traffic separation schemeEnglish
A set of one-way sea lanes, marked on charts and approved by the International Maritime Organization, that keeps ships going in opposite directions apart in crowded waters.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.1 (grade 8)
A set of one-way sea lanes, marked on charts and approved by the International Maritime Organization, that keeps ships going in opposite directions apart in crowded waters.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.1 (grade 8)
trainEnglish
A long line of cars pulled by an engine along a track.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 8.3 (grade K)
A long line of cars pulled by an engine along a track.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 8.3 (grade K)
train ferryEnglish
A ship that carries railway cars across water; on Lake Baikal the icebreaker Baikal carried cars across before a line around the lake was finished.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7)
A ship that carries railway cars across water; on Lake Baikal the icebreaker Baikal carried cars across before a line around the lake was finished.
Geopolitics: The Great Ideas, Lesson 3.3 (grade 9–12) · Grade 7 Geography: Regions of the World, Lesson 2.3 (grade 7)
transcontinentalEnglish
Across the continent. A transcontinental railroad joins one side of the land to the other.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.2 (grade 2)
Across the continent. A transcontinental railroad joins one side of the land to the other.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 8.2 (grade 2)
transcontinental railwayEnglish
A railway that crosses a whole continent, from one ocean to another.
Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
A railway that crosses a whole continent, from one ocean to another.
Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
transform faultEnglish
A plate edge where two plates slide past each other sideways, such as the San Andreas Fault.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
A plate edge where two plates slide past each other sideways, such as the San Andreas Fault.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 9.2 (grade 6)
transitEnglish
One complete trip of a ship through the canal from one ocean to the other.
Grade 7 Geography: Regions of the World, Lesson 8.3 (grade 7) · Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
One complete trip of a ship through the canal from one ocean to the other.
Grade 7 Geography: Regions of the World, Lesson 8.3 (grade 7) · Technology Overcoming Geography, Lesson 3.5 (grade 9–12)
transit of VenusEnglish
The rare time when the planet Venus passes directly between the earth and the sun, so it looks like a small black dot crossing the sun’s face.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.1 (grade 5)
The rare time when the planet Venus passes directly between the earth and the sun, so it looks like a small black dot crossing the sun’s face.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 5.1 (grade 5)
transit passageEnglish
The right, set out in the 1982 United Nations Convention on the Law of the Sea, of ships and aircraft of all nations to pass continuously and quickly through a strait used for international navigation, even when the strait lies inside the territorial sea of the coastal states.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12)
The right, set out in the 1982 United Nations Convention on the Law of the Sea, of ships and aircraft of all nations to pass continuously and quickly through a strait used for international navigation, even when the strait lies inside the territorial sea of the coastal states.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.1 (grade 9–12)
transportation hubEnglish
A place where many routes meet, so people and goods change from one line or vehicle to another.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.2 (grade 8)
A place where many routes meet, so people and goods change from one line or vehicle to another.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.2 (grade 8)
trans-Saharan tradeEnglish
The camel-caravan trade across the Sahara between North Africa and the Sahel, carrying salt, cloth and books south, and gold, ivory and enslaved people north.
Grade 7 Geography: Regions of the World, Lesson 4.3 (grade 7)
The camel-caravan trade across the Sahara between North Africa and the Sahel, carrying salt, cloth and books south, and gold, ivory and enslaved people north.
Grade 7 Geography: Regions of the World, Lesson 4.3 (grade 7)
transshipmentEnglish
Moving cargo from one ship to another at a port partway through its journey, instead of unloading it for local use.
Grade 7 Geography: Regions of the World, Lesson 7.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
Moving cargo from one ship to another at a port partway through its journey, instead of unloading it for local use.
Grade 7 Geography: Regions of the World, Lesson 7.2 (grade 7) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 4.2 (grade 8) · Geography and History: Why Borders Fall Where They Do, Lesson 7.5 (grade 9–12)
transshipment hubEnglish
A port where containers are moved from one ship to another, often from a large mainline ship to smaller feeder ships, without ever leaving the port.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12)
A port where containers are moved from one ship to another, often from a large mainline ship to smaller feeder ships, without ever leaving the port.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.3 (grade 9–12)
trapperEnglish
A man who caught beavers and other animals for their furs.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.4 (grade 2)
A man who caught beavers and other animals for their furs.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.4 (grade 2)
traverse boardEnglish
A wooden board with pegs and holes on which sailors recorded the ship’s direction and speed each half hour of a watch.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
A wooden board with pegs and holes on which sailors recorded the ship’s direction and speed each half hour of a watch.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.3 (grade 5)
travoisEnglish
Say it “tra-VOY.” Two poles tied together to make a sled with no wheels, pulled by a dog or a horse to carry loads.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.2 (grade 2)
Say it “tra-VOY.” Two poles tied together to make a sled with no wheels, pulled by a dog or a horse to carry loads.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.2 (grade 2)
treasure mapEnglish
A map that shows the way to something hidden. An X often marks the spot.
Grade 1 Geography: Maps and Journeys, Lesson 9.3 (grade 1)
A map that shows the way to something hidden. An X often marks the spot.
Grade 1 Geography: Maps and Journeys, Lesson 9.3 (grade 1)
treasure ship (baochuan)English
The largest ships of Zheng He’s fleets, built at the Longjiang yards in Nanjing and filled with silks, porcelain and other gifts for foreign rulers.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
The largest ships of Zheng He’s fleets, built at the Longjiang yards in Nanjing and filled with silks, porcelain and other gifts for foreign rulers.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
Treaty of Brest-LitovskEnglish
The treaty of March 3, 1918, by which Bolshevik Russia left the First World War and gave up Poland, the Baltic lands, Finland and Ukraine to German and Austrian control or to independence.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
The treaty of March 3, 1918, by which Bolshevik Russia left the First World War and gave up Poland, the Baltic lands, Finland and Ukraine to German and Austrian control or to independence.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
Treaty of LausanneEnglish
The treaty of July 24, 1923, between the Allies and the Turkish nationalist government that replaced the Treaty of Sèvres and fixed most of the borders of modern Turkey.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
The treaty of July 24, 1923, between the Allies and the Turkish nationalist government that replaced the Treaty of Sèvres and fixed most of the borders of modern Turkey.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
Treaty of SugauliEnglish
The treaty (signed 1815, ratified 1816) that ended the Anglo-Nepalese War and fixed much of Nepal’s border with British India.
Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12)
The treaty (signed 1815, ratified 1816) that ended the Anglo-Nepalese War and fixed much of Nepal’s border with British India.
Geography and History: Why Borders Fall Where They Do, Lesson 3.3 (grade 9–12)
Treaty of TordesillasEnglish
The treaty signed June 7, 1494, at Tordesillas in Castile, by which Spain and Portugal agreed to divide newly reached lands along a meridian 370 leagues west of the Cape Verde Islands: Spain to the west, Portugal to the east.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
The treaty signed June 7, 1494, at Tordesillas in Castile, by which Spain and Portugal agreed to divide newly reached lands along a meridian 370 leagues west of the Cape Verde Islands: Spain to the west, Portugal to the east.
Geography and History: Why Borders Fall Where They Do, Lesson 9.1 (grade 9–12)
treaty portEnglish
A Chinese port city that China was forced by treaty to open to foreign traders and residents in the 1800s, such as Shanghai.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
A Chinese port city that China was forced by treaty to open to foreign traders and residents in the 1800s, such as Shanghai.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
trestleEnglish
A bridge built of a framework of timbers or iron that carries a railroad across a valley.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.2 (grade 4)
A bridge built of a framework of timbers or iron that carries a railroad across a valley.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 7.2 (grade 4)
tributary systemEnglish
The Chinese practice of treating foreign rulers as vassals who sent “tribute” to the emperor and received rich gifts and trading rights in return.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
The Chinese practice of treating foreign rulers as vassals who sent “tribute” to the emperor and received rich gifts and trading rights in return.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
tribute grainEnglish
Rice and other grain sent as taxes from the provinces to feed the capital, the court and the army.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8)
Rice and other grain sent as taxes from the provinces to feed the capital, the court and the army.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.1 (grade 8)
trilaterationEnglish
Finding a position from its distances to several known points, where the circles (or spheres) of those distances cross.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8) · Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
Finding a position from its distances to several known points, where the circles (or spheres) of those distances cross.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.3 (grade 8) · Technology Overcoming Geography, Lesson 5.2 (grade 9–12)
triviaEnglish
Short questions with quick answers, used in a game.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.4 (grade 3)
Short questions with quick answers, used in a game.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 9.4 (grade 3)
Tropic of Cancer and Tropic of CapricornEnglish
The lines of latitude about 23.4° north and 23.4° south. Between them, the noon sun is straight overhead on at least one day each year.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.2 (grade 6)
The lines of latitude about 23.4° north and 23.4° south. Between them, the noon sun is straight overhead on at least one day each year.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.2 (grade 6)
tropical rain forestEnglish
A thick, evergreen forest near the equator where it is warm all year and rain falls in nearly every month.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
A thick, evergreen forest near the equator where it is warm all year and rain falls in nearly every month.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6) · Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
truthfulnessEnglish
Telling and recording what really happened, even when the truth is disappointing or makes you look small.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.4 (grade 5)
Telling and recording what really happened, even when the truth is disappointing or makes you look small.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.4 (grade 5)
tsetse flyEnglish
An African fly found in wetter savanna and forest that spreads sleeping sickness in people and a deadly disease in cattle and horses.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
An African fly found in wetter savanna and forest that spreads sleeping sickness in people and a deadly disease in cattle and horses.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
tumenEnglish
A Mongol army unit of about 10,000 men, made of ten units of 1,000, each of ten units of 100, each of ten units of 10.
Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
A Mongol army unit of about 10,000 men, made of ten units of 1,000, each of ten units of 100, each of ten units of 10.
Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
tundraEnglish
A cold, treeless biome of low plants (mosses, lichens, sedges, dwarf shrubs) beyond the tree line, in the Arctic or high on mountains.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6) · Grade 1 Life Science: Animal Homes and Habits, Lesson 5.3 (grade 1)
A cold, treeless biome of low plants (mosses, lichens, sedges, dwarf shrubs) beyond the tree line, in the Arctic or high on mountains.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.4 (grade 6) · Grade 1 Life Science: Animal Homes and Habits, Lesson 5.3 (grade 1)
tunnel boring machine (TBM)English
A huge machine with a rotating cutting head that grinds through rock or soil, removes the spoil and lines the tunnel behind it as it advances.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
A huge machine with a rotating cutting head that grinds through rock or soil, removes the spoil and lines the tunnel behind it as it advances.
Technology Overcoming Geography, Lesson 2.5 (grade 9–12)
Turkish StraitsEnglish
The Bosporus, the Sea of Marmara and the Dardanelles together, the only sea route between the Black Sea and the Mediterranean.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.2 (grade 8)
The Bosporus, the Sea of Marmara and the Dardanelles together, the only sea route between the Black Sea and the Mediterranean.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.2 (grade 8)
twist lockEnglish
A locking device that fits into a container’s corner fittings and turns to fasten it to a crane, a truck chassis, a railcar or another container.
Technology Overcoming Geography, Lesson 4.5 (grade 9–12)
A locking device that fits into a container’s corner fittings and turns to fasten it to a crane, a truck chassis, a railcar or another container.
Technology Overcoming Geography, Lesson 4.5 (grade 9–12)
twist lock and corner castingEnglish
The steel fittings at each corner of a container and the rotating locks that grip them, so boxes can be stacked, lifted and locked to a truck chassis, railcar or deck.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
The steel fittings at each corner of a container and the rotating locks that grip them, so boxes can be stacked, lifted and locked to a truck chassis, railcar or deck.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.2 (grade 9–12)
two spheresEnglish
The idea in the 1823 message that the Old World and the New World had different political systems and should stay out of each other’s affairs.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
The idea in the 1823 message that the Old World and the New World had different political systems and should stay out of each other’s affairs.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
two-layer flowEnglish
A current pattern in which water flows one way at the surface and the opposite way near the bottom, because the two seas have different salinities.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12)
A current pattern in which water flows one way at the surface and the opposite way near the bottom, because the two seas have different salinities.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.3 (grade 9–12)
two-ocean navyEnglish
A navy strong enough to defend both the Atlantic and the Pacific at the same time, authorized by Congress in July 1940.
Geography and History: Why Borders Fall Where They Do, Lesson 8.5 (grade 9–12)
A navy strong enough to defend both the Atlantic and the Pacific at the same time, authorized by Congress in July 1940.
Geography and History: Why Borders Fall Where They Do, Lesson 8.5 (grade 9–12)
U
ubiquitous materialEnglish
An input found nearly everywhere, such as water or air, which adds weight to a product without pulling the factory toward any one source.
Human Geography, Lesson 8.2 (grade 9–12)
An input found nearly everywhere, such as water or air, which adds weight to a product without pulling the factory toward any one source.
Human Geography, Lesson 8.2 (grade 9–12)
under-keel clearanceEnglish
The safety margin of water between the bottom of a ship’s keel and the seabed.
Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
The safety margin of water between the bottom of a ship’s keel and the seabed.
Geography and History: Why Borders Fall Where They Do, Lesson 6.5 (grade 9–12)
understoryEnglish
The dim layer of young trees, palms and shrubs below the canopy.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6)
The dim layer of young trees, palms and shrubs below the canopy.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 6.1 (grade 6)
unequal treatiesEnglish
The name Chinese governments and historians give to nineteenth-century treaties forced on Qing China by stronger powers, including Aigun (1858) and Peking (1860).
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
The name Chinese governments and historians give to nineteenth-century treaties forced on Qing China by stronger powers, including Aigun (1858) and Peking (1860).
Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
unimpairedEnglish
Not damaged or spoiled; kept in good condition.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.4 (grade 4)
Not damaged or spoiled; kept in good condition.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 9.4 (grade 4)
unitary stateEnglish
A state in which the national government holds final power and local governments have only the powers it grants them, as in France, Japan and the United Kingdom.
Human Geography, Lesson 5.3 (grade 9–12)
A state in which the national government holds final power and local governments have only the powers it grants them, as in France, Japan and the United Kingdom.
Human Geography, Lesson 5.3 (grade 9–12)
United NationsEnglish
An organization of the world’s countries founded in 1945; as of 2026 it has 193 member states.
Grade 7 Geography: Regions of the World, Lesson 9.2 (grade 7)
An organization of the world’s countries founded in 1945; as of 2026 it has 193 member states.
Grade 7 Geography: Regions of the World, Lesson 9.2 (grade 7)
United Nations (UN)English
The worldwide organization of states founded in 1945 to keep international peace and promote cooperation; 193 member states as of 2026, headquartered in New York.
Human Geography, Lesson 5.4 (grade 9–12)
The worldwide organization of states founded in 1945 to keep international peace and promote cooperation; 193 member states as of 2026, headquartered in New York.
Human Geography, Lesson 5.4 (grade 9–12)
universalizing religionEnglish
A religion that seeks converts among all peoples everywhere (Christianity, Islam, Buddhism), in contrast to an ethnic religion tied to one people and land.
Human Geography, Lesson 4.2 (grade 9–12) · Human Geography, Lesson 4.3 (grade 9–12)
A religion that seeks converts among all peoples everywhere (Christianity, Islam, Buddhism), in contrast to an ethnic religion tied to one people and land.
Human Geography, Lesson 4.2 (grade 9–12) · Human Geography, Lesson 4.3 (grade 9–12)
unrestricted submarine warfareEnglish
Sinking merchant ships without warning, including neutral ships in declared zones. Germany adopted it in February 1917 and again in the Second World War.
Geopolitics: The Great Ideas, Lesson 2.5 (grade 9–12)
Sinking merchant ships without warning, including neutral ships in declared zones. Germany adopted it in February 1917 and again in the Second World War.
Geopolitics: The Great Ideas, Lesson 2.5 (grade 9–12)
upwellingEnglish
Cold water rising from the deep to the surface, often where winds push coastal water out to sea.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.2 (grade 6)
Cold water rising from the deep to the surface, often where winds push coastal water out to sea.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 7.2 (grade 6)
Ural MountainsEnglish
A low, old mountain chain about 2,500 km (1,550 mi) long that runs north to south through Russia and is the traditional boundary between Europe and Asia.
Grade 7 Geography: Regions of the World, Lesson 2.1 (grade 7)
A low, old mountain chain about 2,500 km (1,550 mi) long that runs north to south through Russia and is the traditional boundary between Europe and Asia.
Grade 7 Geography: Regions of the World, Lesson 2.1 (grade 7)
urbanizationEnglish
The growth in the share of a population living in cities and towns, mainly through migration from the countryside.
Human Geography, Lesson 3.3 (grade 9–12) · Human Geography, Lesson 7.1 (grade 9–12)
The growth in the share of a population living in cities and towns, mainly through migration from the countryside.
Human Geography, Lesson 3.3 (grade 9–12) · Human Geography, Lesson 7.1 (grade 9–12)
U.S. Army Corps of EngineersEnglish
The army’s engineering branch, which builds and keeps the nation’s large flood-control works, locks and navigation channels.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.2 (grade 6)
The army’s engineering branch, which builds and keeps the nation’s large flood-control works, locks and navigation channels.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 8.2 (grade 6)
uti possidetisEnglish
Latin, “as you possess.” In modern African and Latin American history, the principle that new states keep the borders of the colonies they replaced.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
Latin, “as you possess.” In modern African and Latin American history, the principle that new states keep the borders of the colonies they replaced.
Geography and History: Why Borders Fall Where They Do, Lesson 9.2 (grade 9–12)
V
value densityEnglish
How much a good is worth for each unit of its weight (for example, silver coins per kilogram). Goods with high value density can bear high transport costs.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
How much a good is worth for each unit of its weight (for example, silver coins per kilogram). Goods with high value density can bear high transport costs.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.3 (grade 9–12)
value-to-weight ratioEnglish
How much a good is worth for each kilogram or pound. Goods with a high ratio can bear the high cost of air freight.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
How much a good is worth for each kilogram or pound. Goods with a high ratio can bear the high cost of air freight.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 5.4 (grade 9–12)
vector and raster dataEnglish
Vector data stores features as points (a pump), lines (a street) and polygons (a census tract). Raster data stores a grid of cells, each with a value (a satellite image, an elevation model).
Human Geography, Lesson 1.3 (grade 9–12)
Vector data stores features as points (a pump), lines (a street) and polygons (a census tract). Raster data stores a grid of cells, each with a value (a satellite image, an elevation model).
Human Geography, Lesson 1.3 (grade 9–12)
vector controlEnglish
Stopping a disease by attacking the animal that carries it, here the mosquito, by draining, screening, oiling and fumigating.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
Stopping a disease by attacking the animal that carries it, here the mosquito, by draining, screening, oiling and fumigating.
Technology Overcoming Geography, Lesson 3.3 (grade 9–12)
vertical exaggerationEnglish
Making the heights on a model taller than true scale so the hills and mountains are easy to see.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.4 (grade 4) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.4 (grade 6) · +2 more
Making the heights on a model taller than true scale so the hills and mountains are easy to see.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.4 (grade 4) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6) · Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.4 (grade 6) · +2 more
vertical scaleEnglish
How much real height each unit of the model’s height stands for, such as 1 cm = 250 m.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6)
How much real height each unit of the model’s height stands for, such as 1 cm = 250 m.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 1.3 (grade 6)
very large crude carrier (VLCC)English
A supertanker that carries about 2 million barrels of crude oil, typically about 330 m (1,080 ft) long.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12)
A supertanker that carries about 2 million barrels of crude oil, typically about 330 m (1,080 ft) long.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12)
vetoEnglish
The power of a single member to block a decision. Each of the five permanent members of the UN Security Council holds a veto.
Human Geography, Lesson 5.4 (grade 9–12) · Grade 8 Latin, Lesson 1.1 (grade 8)
The power of a single member to block a decision. Each of the five permanent members of the UN Security Council holds a veto.
Human Geography, Lesson 5.4 (grade 9–12) · Grade 8 Latin, Lesson 1.1 (grade 8)
vexillologyEnglish
The study of flags, from the Latin vexillum, a Roman banner.
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
The study of flags, from the Latin vexillum, a Roman banner.
Grade 7 Geography: Regions of the World, Lesson 9.4 (grade 7)
Via AppiaEnglish
The Appian Way, begun in 312 B.C. by the censor Appius Claudius Caecus from Rome to Capua and later extended to the port of Brundisium (Brindisi). The poet Statius called it the queen of the long roads.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12) · Grade 5 Latin, Lesson 5.1 (grade 5)
The Appian Way, begun in 312 B.C. by the censor Appius Claudius Caecus from Rome to Capua and later extended to the port of Brundisium (Brindisi). The poet Statius called it the queen of the long roads.
Technology Overcoming Geography, Lesson 2.1 (grade 9–12) · Grade 5 Latin, Lesson 5.1 (grade 5)
vilayetEnglish
A province of the Ottoman Empire. Iraq was formed from the three vilayets of Mosul, Baghdad and Basra.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
A province of the Ottoman Empire. Iraq was formed from the three vilayets of Mosul, Baghdad and Basra.
Geography and History: Why Borders Fall Where They Do, Lesson 9.3 (grade 9–12)
vistaEnglish
The cleared strip along a boundary through forest. Along the U.S.–Canada border it is kept about 20 feet (6 m) wide, 10 feet on each side.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
The cleared strip along a boundary through forest. Along the U.S.–Canada border it is kept about 20 feet (6 m) wide, 10 feet on each side.
Geography and History: Why Borders Fall Where They Do, Lesson 10.4 (grade 9–12)
VLCCEnglish
Very Large Crude Carrier, a supertanker that carries about 2 million barrels of crude oil.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.4 (grade 9–12)
Very Large Crude Carrier, a supertanker that carries about 2 million barrels of crude oil.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.4 (grade 9–12)
VOCEnglish
Vereenigde Oostindische Compagnie, the United East India Company, chartered by the States General of the Dutch Republic on March 20, 1602, with a monopoly of Dutch trade east of the Cape of Good Hope.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
Vereenigde Oostindische Compagnie, the United East India Company, chartered by the States General of the Dutch Republic on March 20, 1602, with a monopoly of Dutch trade east of the Cape of Good Hope.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.4 (grade 9–12)
volcanic beltEnglish
A line of volcanoes. Mexico’s Trans-Mexican Volcanic Belt crosses the country from west to east south of Mexico City, and another chain runs along the Pacific side of Central America.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
A line of volcanoes. Mexico’s Trans-Mexican Volcanic Belt crosses the country from west to east south of Mexico City, and another chain runs along the Pacific side of Central America.
Grade 7 Geography: Regions of the World, Lesson 8.2 (grade 7)
von Thünen modelEnglish
A model, published by Johann Heinrich von Thünen in 1826, that predicts rings of agricultural land use around a single market town, based on the cost of transporting each product.
Human Geography, Lesson 6.2 (grade 9–12)
A model, published by Johann Heinrich von Thünen in 1826, that predicts rings of agricultural land use around a single market town, based on the cost of transporting each product.
Human Geography, Lesson 6.2 (grade 9–12)
V-shaped valleyEnglish
A narrow, deep valley cut by a fast, steep river that wears mostly downward; the upper course of a river.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6)
A narrow, deep valley cut by a fast, steep river that wears mostly downward; the upper course of a river.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 4.2 (grade 6)
W
wadiEnglish
A desert valley or streambed that is dry most of the year but can carry sudden floods after a storm.
Grade 7 Geography: Regions of the World, Lesson 3.2 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
A desert valley or streambed that is dry most of the year but can carry sudden floods after a storm.
Grade 7 Geography: Regions of the World, Lesson 3.2 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 4.2 (grade 9–12)
wagon trainEnglish
A long line of covered wagons traveling together.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.4 (grade 2)
A long line of covered wagons traveling together.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.4 (grade 2)
walking cityEnglish
A compact city of the era before mechanized transit, in which nearly everything lay within a walk of about 30 minutes, so homes, shops and workplaces were mixed close together.
Human Geography, Lesson 7.4 (grade 9–12)
A compact city of the era before mechanized transit, in which nearly everything lay within a walk of about 30 minutes, so homes, shops and workplaces were mixed close together.
Human Geography, Lesson 7.4 (grade 9–12)
Wallace LineEnglish
A boundary through the Lombok Strait and the Makassar Strait, traced by Alfred Russel Wallace, that separates mostly Asian animals to the west from mostly Australian kinds to the east.
Grade 7 Geography: Regions of the World, Lesson 7.1 (grade 7)
A boundary through the Lombok Strait and the Makassar Strait, traced by Alfred Russel Wallace, that separates mostly Asian animals to the west from mostly Australian kinds to the east.
Grade 7 Geography: Regions of the World, Lesson 7.1 (grade 7)
war of annihilationEnglish
The Nazi leadership’s plan for the war in the East as a racial war to destroy the Soviet state, murder Jews and communist officials, and starve and enslave the Slavic peoples.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
The Nazi leadership’s plan for the war in the East as a racial war to destroy the Soviet state, murder Jews and communist officials, and starve and enslave the Slavic peoples.
Geography and History: Why Borders Fall Where They Do, Lesson 7.4 (grade 9–12)
wardEnglish
In Oglethorpe’s Savannah, a neighborhood unit built around a public square, with house lots to the north and south and trust lots to the east and west.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
In Oglethorpe’s Savannah, a neighborhood unit built around a public square, with house lots to the north and south and trust lots to the east and west.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 8.3 (grade 8)
warm-water portEnglish
A harbor whose water does not freeze in winter, so ships can use it all year. Also called an ice-free port.
Grade 7 Geography: Regions of the World, Lesson 2.2 (grade 7)
A harbor whose water does not freeze in winter, so ships can use it all year. Also called an ice-free port.
Grade 7 Geography: Regions of the World, Lesson 2.2 (grade 7)
war-risk insuranceEnglish
Extra insurance that shipowners must buy to send a ship into waters where it might be attacked. Its cost rises sharply when a strait becomes dangerous.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12)
Extra insurance that shipowners must buy to send a ship into waters where it might be attacked. Its cost rises sharply when a strait becomes dangerous.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.2 (grade 9–12)
Washington, D.C.English
The capital city of the whole United States, where the President lives and Congress meets. D.C. stands for District of Columbia.
Grade 1 Geography: Maps and Journeys, Lesson 6.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.2 (grade 2)
The capital city of the whole United States, where the President lives and Congress meets. D.C. stands for District of Columbia.
Grade 1 Geography: Maps and Journeys, Lesson 6.2 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.2 (grade 2)
water powerEnglish
The push of moving or falling water, used to turn a wheel that runs machines.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.1 (grade 4) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
The push of moving or falling water, used to turn a wheel that runs machines.
Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 2.1 (grade 4) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.3 (grade 8)
waterfallEnglish
A place where a river drops over a cliff.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.4 (grade 3)
A place where a river drops over a cliff.
Grade 1 Geography: Maps and Journeys, Lesson 6.3 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 3.4 (grade 3)
watershed (divide)English
A ridge of high land that separates rivers flowing toward different seas.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
A ridge of high land that separates rivers flowing toward different seas.
Grade 7 Geography: Regions of the World, Lesson 1.3 (grade 7) · Geography and History: Why Borders Fall Where They Do, Lesson 2.4 (grade 9–12)
watershed divideEnglish
The high ground that separates land draining to one river system or ocean from land draining to another. The Eastern Continental Divide separates Atlantic rivers from rivers that reach the Gulf of Mexico by way of the Ohio and Mississippi.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
The high ground that separates land draining to one river system or ocean from land draining to another. The Eastern Continental Divide separates Atlantic rivers from rivers that reach the Gulf of Mexico by way of the Ohio and Mississippi.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
watershed (drainage basin)English
All the land whose rain drains into one river; the Chagres watershed sends its floods straight across the canal route.
Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
All the land whose rain drains into one river; the Chagres watershed sends its floods straight across the canal route.
Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
watershed (water-parting)English
The line along a ridge that separates water flowing to one side from water flowing to the other. Many treaties use it to define a mountain border.
Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
The line along a ridge that separates water flowing to one side from water flowing to the other. Many treaties use it to define a mountain border.
Geography and History: Why Borders Fall Where They Do, Lesson 3.1 (grade 9–12)
wayfindingEnglish
Finding the way across the ocean without instruments, by reading the stars, sun, swells, winds, birds and clouds.
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
Finding the way across the ocean without instruments, by reading the stars, sun, swells, winds, birds and clouds.
Grade 7 Geography: Regions of the World, Lesson 7.4 (grade 7)
weight-losing materialEnglish
A raw material that loses much of its weight in processing (like coal, which is burned away), so it pays to process it near where it is dug.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
A raw material that loses much of its weight in processing (like coal, which is burned away), so it pays to process it near where it is dug.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 4.3 (grade 9–12)
Western CordilleraEnglish
The belt of mountain ranges in western Canada, including the Rocky Mountains, the Selkirks and the Coast Mountains.
Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
The belt of mountain ranges in western Canada, including the Rocky Mountains, the Selkirks and the Coast Mountains.
Grade 7 Geography: Regions of the World, Lesson 8.1 (grade 7)
Western GhatsEnglish
A long range of steep hills along India’s west coast that catches the monsoon rain before it reaches the Deccan Plateau.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
A long range of steep hills along India’s west coast that catches the monsoon rain before it reaches the Deccan Plateau.
Grade 7 Geography: Regions of the World, Lesson 5.1 (grade 7)
Western HemisphereEnglish
The half of the earth west of the prime meridian and east of the 180th meridian, by the usual convention; in politics, North and South America and the nearby islands. Its edges are a mapmaker’s choice, not a wall.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
The half of the earth west of the prime meridian and east of the 180th meridian, by the usual convention; in politics, North and South America and the nearby islands. Its edges are a mapmaker’s choice, not a wall.
Geopolitics: The Great Ideas, Lesson 4.3 (grade 9–12)
wet and dry seasonsEnglish
In the tropics, the year is divided by rain rather than by cold: months when the rain belt is overhead, and months when it is not.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
In the tropics, the year is divided by rain rather than by cold: months when the rain belt is overhead, and months when it is not.
Grade 7 Geography: Regions of the World, Lesson 4.2 (grade 7)
wet dockEnglish
An enclosed basin with gates, where water is kept at a steady level so ships stay afloat whatever the tide is doing outside.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
An enclosed basin with gates, where water is kept at a steady level so ships stay afloat whatever the tide is doing outside.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 3.3 (grade 8)
wet seasonEnglish
The part of the year when most of the rain falls. In Calabar it runs from about April to October.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5)
The part of the year when most of the rain falls. In Calabar it runs from about April to October.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.4 (grade 5)
Wilderness RoadEnglish
The route Daniel Boone’s axmen blazed in 1775 from the Holston River through the Cumberland Gap into Kentucky; widened for wagons in 1796.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
The route Daniel Boone’s axmen blazed in 1775 from the Holston River through the Cumberland Gap into Kentucky; widened for wagons in 1796.
Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12)
wind roseEnglish
A circle or star of direction lines, each named for the wind that blows from that direction.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.4 (grade 3)
A circle or star of direction lines, each named for the wind that blows from that direction.
Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.4 (grade 3)
windwardEnglish
The side of a mountain range that faces the oncoming wind. Rising air there makes clouds and heavy rain or snow.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6)
The side of a mountain range that faces the oncoming wind. Rising air there makes clouds and heavy rain or snow.
Grade 6 Geography: Physical Geography: The Earth’s Systems, Lesson 5.3 (grade 6)
woodlandsEnglish
Land covered with forests of tall trees, with rain for crops and rivers and lakes for fish.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.1 (grade 2)
Land covered with forests of tall trees, with rain for crops and rivers and lakes for fish.
Grade 2 Geography: Our Country, Coast to Coast, Lesson 6.1 (grade 2)
world mapEnglish
A flat picture of the whole earth, with all the land and all the water.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.1 (grade K)
A flat picture of the whole earth, with all the land and all the water.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 7.1 (grade K)
World-IslandEnglish
Europe, Asia and Africa considered as one continuous landmass, joined at Suez, which Mackinder called the greatest island on earth.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
Europe, Asia and Africa considered as one continuous landmass, joined at Suez, which Mackinder called the greatest island on earth.
Geopolitics: The Great Ideas, Lesson 3.2 (grade 9–12)
world-systems theoryEnglish
Immanuel Wallerstein’s model (1974) of a single world economy divided into a core, a semi-periphery and a periphery, linked by trade and the division of labor.
Human Geography, Lesson 8.3 (grade 9–12)
Immanuel Wallerstein’s model (1974) of a single world economy divided into a core, a semi-periphery and a periphery, linked by trade and the division of labor.
Human Geography, Lesson 8.3 (grade 9–12)
X
X marks the spotEnglish
An X drawn on a map to show where something is hidden.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.1 (grade K)
An X drawn on a map to show where something is hidden.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 9.1 (grade K)
XiongnuEnglish
A confederation of horse-riding nomads on the steppe north of China, the Han dynasty’s great rival in the 200s and 100s B.C.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12)
A confederation of horse-riding nomads on the steppe north of China, the Han dynasty’s great rival in the 200s and 100s B.C.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.1 (grade 9–12)
Y
yamEnglish
The Mongol network of relay stations along the main roads, with fresh horses, food and lodging for official messengers and travelers carrying a pass.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
The Mongol network of relay stations along the main roads, with fresh horses, food and lodging for official messengers and travelers carrying a pass.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.4 (grade 9–12) · Geography and History: Why Borders Fall Where They Do, Lesson 4.4 (grade 9–12)
Yangtze RiverEnglish
China’s longest river, about 3,900 miles (6,300 km) long, flowing east across the middle of China to the sea at Shanghai.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
China’s longest river, about 3,900 miles (6,300 km) long, flowing east across the middle of China to the sea at Shanghai.
Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 6.3 (grade 5)
yardEnglish
The land right around a house, where you can play or plant a garden.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.3 (grade K) · Fabrics & Sewing I, Lesson 4.4 (grade 3–5)
The land right around a house, where you can play or plant a garden.
Kindergarten Geography: God Made the Earth: My First Maps, Lesson 1.3 (grade K) · Fabrics & Sewing I, Lesson 4.4 (grade 3–5)
yellow feverEnglish
A deadly disease caused by a virus and spread by the bite of the Aedes aegypti mosquito.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.3 (grade 8) · Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
A deadly disease caused by a virus and spread by the bite of the Aedes aegypti mosquito.
Grade 8 Geography: Rivers, Ports and Straits, Lesson 6.3 (grade 8) · Technology Overcoming Geography, Lesson 3.2 (grade 9–12)
Yongle EmperorEnglish
Zhu Di, third emperor of the Ming (reigned 1402–1424), who seized the throne from his nephew, moved the capital to Beijing and sent out the treasure fleets.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
Zhu Di, third emperor of the Ming (reigned 1402–1424), who seized the throne from his nephew, moved the capital to Beijing and sent out the treasure fleets.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
Z
zenith sectorEnglish
A long telescope hung from a pivot and aimed nearly straight up, with a plumb line and a finely divided arc, used to measure how far a star passes from the zenith (the point directly overhead).
Geography and History: Why Borders Fall Where They Do, Lesson 10.1 (grade 9–12)
A long telescope hung from a pivot and aimed nearly straight up, with a plumb line and a finely divided arc, used to measure how far a star passes from the zenith (the point directly overhead).
Geography and History: Why Borders Fall Where They Do, Lesson 10.1 (grade 9–12)
zhangEnglish
A Chinese unit of length equal to 10 chi (Chinese feet). The Ming chi varied, so a zhang was roughly 3.1 m (about 10 ft), which makes the size of the ships hard to pin down.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)
A Chinese unit of length equal to 10 chi (Chinese feet). The Ming chi varied, so a zhang was roughly 3.1 m (about 10 ft), which makes the size of the ships hard to pin down.
Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.3 (grade 9–12)