English terms: Explore

3-1-1 ruleEnglish
The TSA rule for liquids in carry-ons: containers of 3.4 ounces (100 milliliters) or less, all in one quart-size bag, one bag per passenger.
Explore Travel and Faraway Places · Expert, Stop 2.5 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.5 (Ages 10–13)

abbessEnglish
A woman who leads a community of nuns, or, in Hilda’s case, a double monastery.
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abolitionistEnglish
A person who worked to abolish (end) slavery. Many were moved by Christian conviction, such as the Quaker Thomas Garrett of Wilmington.
Explore Heroines of History and Faith · Expert, Stop 4.3 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 4.3 (Ages 10–13)

Acinonyx jubatusEnglish
The scientific name of the cheetah. It is the only living member of its genus and differs from the other big cats in many ways.
Explore Animals · Expert, Stop 1.8 (Ages 14+)

acrosticEnglish
A poem in which each line or verse begins with the next letter of the alphabet. Proverbs 31:10–31 has 22 verses, one for each letter of the Hebrew alphabet.
Explore Hospitality and Home · Expert, Stop 4.1 (Ages 14+)

activityEnglish
Something fun to do together, like a game or craft.
Explore Hospitality and Home, Stop 3.8 (Ages 7–9)

Acts and MonumentsEnglish
John Foxe’s huge history of Christian martyrs (first English edition 1563), known as Foxe’s Book of Martyrs. It made Jane a Protestant heroine for centuries.
Explore Heroines of History and Faith · Expert, Stop 3.2 (Ages 14+)

AdamEnglish
The first man, whom God made from the dust of the ground (Genesis 2:7).
Explore Animals, Stop 6.10 (Ages 7–9)

addressEnglish
A speech given to a crowd on a special occasion.
Explore Great Battles, Stop 4.7 (Ages 7–9) · Explore Hospitality and Home, Stop 3.4 (Ages 7–9) · Grade 1 Geography: Maps and Journeys, Lesson 2.4 (grade 1) · +2 more

admiralEnglish
The commander of a fleet of warships.
Explore Great Battles, Stop 3.8 (Ages 7–9) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 2.4 (grade 5)

AfricanusEnglish
The honorary surname given to Scipio for his victory in Africa; he is known as Scipio Africanus.
Explore Great Battles · Expert, Stop 1.6 (Ages 14+)

afternoon teaEnglish
A light meal of tea, sandwiches, scones and cakes served in the late afternoon, about four or five o’clock, popularized in England in the 1840s.
Explore Hospitality and Home · Expert, Stop 2.8 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.8 (Ages 10–13) · Explore Hospitality and Home, Stop 2.8 (Ages 7–9)

age segregationEnglish
A pattern in which young and adult animals gather in separate groups.
Explore Dinosaurs · Expert, Stop 3.4 (Ages 14+)

aggressive mimicryEnglish
When a predator imitates a harmless signal to lure prey, as when a Photuris female copies the answer flash of another species.
Explore Animals · Expert, Stop 5.6 (Ages 14+)

AhasuerusEnglish
The Hebrew name of the Persian king in Esther, usually identified with Xerxes I, who ruled 486–465 B.C.
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Aida clothEnglish
A cotton even-weave fabric woven in clear blocks with holes at each corner, made for counted cross-stitch; sold by count, such as 11, 14, 16 or 18 squares per inch.
Explore Crafts and Making · Expert, Stop 2.7 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 2.7 (Ages 10–13) · Explore Crafts and Making, Stop 2.7 (Ages 7–9)

air sacEnglish
A thin, balloon-like extension of the breathing system. In birds, air sacs push air through the lungs in one direction, which is very efficient.
Explore Dinosaurs · Expert, Stop 4.10 (Ages 14+) · Explore Dinosaurs, Stop 3.9 (Ages 7–9) · Explore Dinosaurs, Stop 4.10 (Ages 7–9) · +1 more

air superiorityEnglish
Control of the sky over a battle area, so that one side can fly and the other cannot fly safely.
Explore Great Battles · Expert, Stop 5.4 (Ages 14+)

airborneEnglish
Troops delivered by parachute or glider. Three Allied airborne divisions landed in Normandy the night before the beach landings.
Explore Great Battles · Expert, Stop 5.7 (Ages 14+) · Explore Great Battles, Stop 5.8 (Ages 7–9)

airborne divisionEnglish
A division of soldiers trained to go into battle by parachute or glider.
Explore Great Battles · Ranger, Stop 5.8 (Ages 10–13)

aircraft carrierEnglish
A warship with a flat deck from which airplanes take off and land; by 1942 the most powerful ship in a navy.
Explore Great Battles · Expert, Stop 5.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.5 (Ages 10–13) · Explore Great Battles, Stop 5.5 (Ages 7–9) · +1 more

Ai-weh-dehEnglish
The Chinese name the people of Yangcheng gave Aylward, usually translated “the virtuous one.”
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al-AndalusEnglish
The Arabic name for the lands of Spain and Portugal ruled by Muslims after the conquest that began in 711. In 732 it was a province of the Umayyad Caliphate, ruled from Damascus.
Explore Great Battles · Expert, Stop 2.1 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.1 (Ages 10–13)

alkaloidEnglish
A nitrogen-containing chemical, often bitter or toxic, made by many plants, fungi and small animals. Caffeine and nicotine are alkaloids.
Explore Animals · Expert, Stop 3.9 (Ages 14+) · Explore Animals · Ranger, Stop 3.9 (Ages 10–13)

allometryEnglish
The study of how body proportions change with size; for example, leg bones get thicker faster than they get longer as animals get heavier.
Explore Dinosaurs · Expert, Stop 1.10 (Ages 14+)

allyEnglish
A city or people who agree to fight on the same side. At Thermopylae Sparta fought with allies from many Greek cities.
Explore Great Battles · Ranger, Stop 1.2 (Ages 10–13) · Explore Great Battles, Stop 1.2 (Ages 7–9) · Explore Great Battles, Stop 3.6 (Ages 7–9) · +1 more

almonerEnglish
An old word for a person or office that hands out gifts to those in need. Barton used it for the Red Cross’s role in distributing the public’s gifts.
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almsEnglish
Gifts to the poor.
Explore Heroines of History and Faith, Stop 2.6 (Ages 7–9)

almsgivingEnglish
Giving money, food or help to the poor as an act of love and worship.
Explore Heroines of History and Faith · Ranger, Stop 2.6 (Ages 10–13)

alpEnglish
A high mountain pasture where cattle graze in summer; the mountains are named after these meadows.
Explore Travel and Faraway Places · Ranger, Stop 4.5 (Ages 10–13)

alphabetEnglish
All the letters, A to Z, in order.
Explore Crafts and Making, Stop 2.6 (Ages 7–9) · Grade 4 Greek, Lesson 1.1 (grade 4)

AlpsEnglish
The highest mountain range in Europe, curving across Switzerland, France, Italy, Austria and nearby lands.
Explore Travel and Faraway Places, Stop 4.5 (Ages 7–9)

altarEnglish
A pile of stones where people worshipped God and gave Him offerings.
Explore Travel and Faraway Places, Stop 3.1 (Ages 7–9)

altimeterEnglish
The instrument that tells a pilot the aircraft’s height; Earhart’s failed during the 1932 flight.
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altricialEnglish
Hatched naked or nearly so, with eyes closed and helpless, needing long care in the nest (robins, eagles, songbirds).
Explore Animals · Expert, Stop 2.8 (Ages 14+)

altricial and precocialEnglish
Altricial young are helpless at hatching and need care; precocial young can walk and feed soon after hatching.
Explore Dinosaurs · Expert, Stop 3.8 (Ages 14+)

AmbroseEnglish
The bishop of Milan whose preaching helped bring Augustine to faith and who baptized him in 387.
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amenityEnglish
A comfort or service offered to guests beyond the bed itself, such as a reading chair, fresh flowers, a garden or a packed lunch.
Explore Hospitality and Home · Expert, Stop 4.6 (Ages 14+) · Explore Hospitality and Home, Stop 4.6 (Ages 7–9)

American amendmentEnglish
The idea, pressed by Barton and accepted at the international Red Cross conference in Geneva in 1884, that Red Cross societies should also bring relief in peacetime disasters such as floods, fires and storms.
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American Bison SocietyEnglish
A group founded in 1905 at the Bronx Zoo, with William Hornaday as president and Theodore Roosevelt as honorary president, to save the bison.
Explore Animals · Expert, Stop 1.10 (Ages 14+)

American Expeditionary Forces (AEF)English
The U.S. Army in Europe in World War I, commanded by General John J. Pershing.
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American styleEnglish
A way of eating in which the diner cuts with the knife in the right hand, lays the knife down, and switches the fork to the right hand to eat. It is sometimes called the “zigzag” style.
Explore Hospitality and Home · Ranger, Stop 2.6 (Ages 10–13)

American (zigzag) styleEnglish
Cut with the knife in the right hand and the fork in the left; then lay the knife down, switch the fork to the right hand, and eat.
Explore Hospitality and Home · Expert, Stop 2.6 (Ages 14+)

AmmaEnglish
Tamil for “mother.” The children of Dohnavur called Carmichael Amma.
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ammunitionEnglish
Shells and bullets for guns.
Explore Horses and Ponies, Stop 3.6 (Ages 7–9)

amphibianEnglish
From Greek for “double life”: a cold-blooded animal with moist, glandular skin and no scales that typically begins life in water and later lives partly on land. Frogs, salamanders and caecilians are amphibians.
Explore Animals · Expert, Stop 3.7 (Ages 14+) · Explore Animals · Ranger, Stop 3.7 (Ages 10–13) · Explore Animals, Stop 3.7 (Ages 7–9) · +3 more

amphibious assaultEnglish
An attack launched from the sea onto a defended shore.
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amphibious landingEnglish
Carrying an army by water and putting it ashore to fight on land.
Explore Great Battles · Expert, Stop 4.6 (Ages 14+) · Geography and History: Why Borders Fall Where They Do, Lesson 6.4 (grade 9–12)

amphitheaterEnglish
An oval Roman arena where crowds watched gladiators, wild-beast shows and public executions.
Explore Heroines of History and Faith · Expert, Stop 2.1 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 4.2 (Ages 10–13)

amphitheatreEnglish
From Greek words meaning “theatre on both sides”: an oval or round arena with seats rising all the way around it.
Explore Travel and Faraway Places · Expert, Stop 4.2 (Ages 14+)

ampullae of LorenziniEnglish
Jelly-filled pores on a shark’s snout that sense very weak electric fields, such as those made by the muscles of a hidden fish. Named for Stefano Lorenzini, who described them in 1678.
Explore Animals · Expert, Stop 4.1 (Ages 14+) · Explore Animals · Ranger, Stop 4.1 (Ages 10–13)

Anaconda PlanEnglish
General Winfield Scott’s 1861 strategy to squeeze the Confederacy like a great snake: blockade the coast and take control of the Mississippi River.
Explore Great Battles · Expert, Stop 4.6 (Ages 14+)

anadromousEnglish
Born in fresh water, grows up in the sea and returns to fresh water to spawn (from Greek “running upward”). Salmon, shad and sturgeon are anadromous.
Explore Animals · Expert, Stop 4.8 (Ages 14+) · Explore Animals · Ranger, Stop 4.8 (Ages 10–13)

Andrew JacksonEnglish
The American general who defended New Orleans. He later became the seventh President.
Explore Great Battles, Stop 4.2 (Ages 7–9)

Angevin EmpireEnglish
The name historians give to the lands ruled by Henry II and his sons: England, Normandy, Anjou, Aquitaine and more, from Scotland’s border to the Pyrenees.
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anglerfishEnglish
A fish with a “fishing rod” on its head that has a glowing tip to attract food.
Explore Animals, Stop 4.7 (Ages 7–9)

ankylosaurEnglish
A member of the armored, four-legged plant-eating dinosaurs. Ankylosaurids had tail clubs; nodosaurids had shoulder spikes and no club.
Explore Dinosaurs · Expert, Stop 1.6 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.6 (Ages 10–13)

annulmentEnglish
A church ruling that a marriage was never valid. Eleanor’s first marriage was annulled in 1152 because she and Louis VII were related within the forbidden degrees (consanguinity).
Explore Heroines of History and Faith · Expert, Stop 2.7 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.7 (Ages 10–13)

anointedEnglish
In Hebrew mashiach, “Messiah”: one set apart by God with holy oil, especially a king. Hannah’s song is one of the earliest places in Scripture to call the LORD’s king “his anointed” (1 Samuel 2:10).
Explore Heroines of History and Faith · Expert, Stop 1.5 (Ages 14+)

Anse au FoulonEnglish
A small cove about two miles above Quebec where a narrow path climbed the cliff; the British landing place on September 13, 1759.
Explore Great Battles · Expert, Stop 3.3 (Ages 14+)

anthocyaninsEnglish
The plant pigments that make many reds, purples and blues. They change with acidity and fade in light, so these colors often turn brown or pale when pressed.
Explore Crafts and Making · Expert, Stop 3.6 (Ages 14+)

anticoagulantEnglish
A substance that keeps blood from clotting, so a wound keeps bleeding.
Explore Animals · Expert, Stop 3.2 (Ages 14+)

AntietamEnglish
A battle near Sharpsburg, Maryland, on 17 September 1862, the bloodiest single day in American history.
Explore Heroines of History and Faith · Ranger, Stop 4.2 (Ages 10–13) · Explore Heroines of History and Faith, Stop 4.2 (Ages 7–9)

Antietam (September 17, 1862)English
A Civil War battle near Sharpsburg, Maryland; the bloodiest single day in American history, with about 23,000 men killed, wounded or missing.
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AntiochEnglish
A great city in Syria where believers were first called Christians (Acts 11:26) and from which Paul’s journeys began.
Explore Travel and Faraway Places · Ranger, Stop 3.2 (Ages 10–13)

antithetic parallelismEnglish
A form of Hebrew poetry in which the second line states the opposite of the first, so each line sharpens the other. Proverbs 10–15 is full of it.
Explore Horses and Ponies · Expert, Stop 4.3 (Ages 14+)

antitoxin (serum)English
A medicine made from the blood of immunized horses that neutralizes the diphtheria poison; in 1925 it was called “serum.”
Explore Animals · Expert, Stop 6.8 (Ages 14+) · Explore Animals · Ranger, Stop 6.8 (Ages 10–13)

antivenomEnglish
A medicine made from antibodies (usually raised in horses or sheep) that binds and neutralizes a particular snake venom.
Explore Animals · Expert, Stop 3.3 (Ages 14+)

apex predatorEnglish
A hunter at the top of its food chain, with no natural predators as an adult. Apex predators help keep herds of grazing animals in check.
Explore Animals · Expert, Stop 1.1 (Ages 14+) · Explore Animals · Expert, Stop 4.1 (Ages 14+)

apocalypseEnglish
From the Greek for “unveiling”: the name of the book of Revelation and of writing that reveals God’s purposes through visions.
Explore Horses and Ponies · Expert, Stop 3.2 (Ages 14+)

aposematismEnglish
Warning coloration: bright, easy-to-remember colors or patterns that tell predators an animal is poisonous or dangerous.
Explore Animals · Expert, Stop 3.9 (Ages 14+)

apostleEnglish
“One who is sent”: a messenger commissioned by Christ; Paul called himself the apostle of the Gentiles (Romans 11:13).
Explore Travel and Faraway Places · Expert, Stop 3.2 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.2 (Ages 10–13) · Explore Travel and Faraway Places, Stop 3.2 (Ages 7–9)

appliquéEnglish
Sewing cut shapes of cloth on top of a background cloth, turning the edges under (say “ap-lee-KAY”).
Explore Crafts and Making · Expert, Stop 2.8 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 2.8 (Ages 10–13) · Home Décor, Costume & Upholstery, Lesson 5.1 (grade 9–12)

AppomattoxEnglish
The Virginia village where Lee surrendered to Grant in April 1865 (say “ap-uh-MAT-uks”).
Explore Horses and Ponies, Stop 3.5 (Ages 7–9)

Appomattox Court HouseEnglish
The Virginia village where Lee surrendered the Army of Northern Virginia to Grant on 9 April 1865.
Explore Horses and Ponies · Expert, Stop 3.5 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 3.5 (Ages 10–13)

apprenticeshipEnglish
Learning a craft by working under a master. Exodus 35:34 says God put it in Bezaleel’s and Aholiab’s hearts “that he may teach.”
Explore Crafts and Making · Expert, Stop 4.1 (Ages 14+)

AQHAEnglish
The American Quarter Horse Association, founded in 1940 in Fort Worth, Texas, to register and preserve the breed.
Explore Horses and Ponies · Expert, Stop 1.5 (Ages 14+)

AquitaineEnglish
A large, rich duchy in southwestern France, about a quarter of the modern country, centered on Poitiers and Bordeaux.
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ArabianEnglish
One of the oldest horse breeds, from the deserts of the Arabian Peninsula.
Explore Horses and Ponies, Stop 1.2 (Ages 7–9)

arachnidEnglish
An arthropod with eight legs, two main body parts and no antennae or wings: spiders, scorpions, ticks and mites.
Explore Animals · Expert, Stop 5.4 (Ages 14+) · Explore Animals · Ranger, Stop 5.4 (Ages 10–13) · Explore Animals, Stop 5.4 (Ages 7–9) · +1 more

ArbellaEnglish
The flagship of John Winthrop’s fleet. It brought the Dudley and Bradstreet families to Salem in June 1630.
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ArchaeopteryxEnglish
A feathered animal with wings, teeth and a long bony tail, found in stone in Germany (say “ar-kee-OP-ter-iks”).
Explore Dinosaurs, Stop 3.7 (Ages 7–9) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 5.3 (grade 8)

archetypeEnglish
Owen’s word for an ideal plan, which he held was in the mind of the Creator, underlying the skeletons of all backboned animals.
Explore Dinosaurs · Expert, Stop 2.4 (Ages 14+)

archipelagoEnglish
A group or chain of islands. The Galápagos archipelago lies on the equator about 1,000 kilometers (600 miles) west of Ecuador.
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ArchiteuthisEnglish
The scientific name (genus) of the giant squid, from Greek for “chief squid,” given by the Danish zoologist Japetus Steenstrup in 1857.
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ArdennesEnglish
A region of steep hills, thick forests and narrow valleys in Belgium, Luxembourg and France.
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AreopagusEnglish
“Mars’ hill” in Athens, the hill and council where Paul spoke of “the Unknown God” (Acts 17:22–23).
Explore Travel and Faraway Places · Expert, Stop 3.2 (Ages 14+) · Grade 5 Greek, Lesson 4.1 (grade 5) · Grade 6 Greek, Lesson 3.2 (grade 6)

Argonne ForestEnglish
A forest of steep hills and deep valleys in northeastern France, where Americans fought in 1918.
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ArianEnglish
Following the false teaching of Arius that Jesus is not fully God; many Germanic peoples, including the Burgundians and Goths, held it.
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ArianismEnglish
The teaching of Arius, condemned at the Council of Nicaea in 325, that the Son of God is a created being and not fully equal with the Father. Most Goths and Burgundians held it.
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ark of bulrushesEnglish
The small basket-boat Jochebed made of papyrus, sealed with slime (bitumen) and pitch. The Hebrew word for “ark,” tevah, is used elsewhere in the Bible only for Noah’s ark.
Explore Heroines of History and Faith · Expert, Stop 1.2 (Ages 14+) · Explore Heroines of History and Faith, Stop 1.2 (Ages 7–9)

armadaEnglish
The Spanish word for an armed fleet. In English, “the Armada” usually means the great Spanish fleet sent against England in 1588.
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armisticeEnglish
An agreement to stop fighting. The armistice ending World War I took effect at 11 a.m. on November 11, 1918.
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armorEnglish
A hard covering that protects a body.
Explore Dinosaurs, Stop 1.6 (Ages 7–9) · Grade 2 Life Science: Animal Families, Lesson 7.2 (grade 2) · Grade 3 Life Science: Plants and Animals Together, Lesson 6.3 (grade 3) · +2 more

arousalEnglish
A brief rewarming in the middle of hibernation; arousals use a large share of the stored fat.
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arribadaEnglish
Spanish for “arrival”: a mass nesting in which thousands of ridley turtles come ashore together over a few days.
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A-series sizesEnglish
International paper sizes based on a sheet of one square meter (A0) with sides in the ratio 1 to the square root of 2; each halving (A1, A2, A3, A4 …) keeps the same shape. A4 is 210 by 297 mm.
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asilEnglish
An Arabic word meaning “pure” or “of noble origin,” used by the Bedouin for a horse whose descent, through the mother’s line, was known and trusted.
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asphaltEnglish
Thick, sticky natural petroleum (often called “tar”) that seeps up to the surface at La Brea from the oil field below. Brea is Spanish for tar or pitch.
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assuranceEnglish
Being sure.
Explore Heroines of History and Faith, Stop 4.4 (Ages 7–9)

asteroidEnglish
A big rock flying through space. A small one that hits the earth is called a meteorite.
Explore Dinosaurs, Stop 4.7 (Ages 7–9)

ASTM/SEI helmetEnglish
An equestrian helmet tested to the ASTM F1163 standard and certified by the Safety Equipment Institute; replaced after any hard fall.
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astrideEnglish
Riding with one leg on each side of the horse, instead of sideways in a sidesaddle, as most ladies rode then.
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asymmetricalEnglish
Not the same on both sides. In many owls, one ear opening sits higher on the head than the other.
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asymmetrical earsEnglish
Ear openings set at different heights on the two sides of the head, so a sound reaches each ear a little differently depending on whether it comes from above or below.
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at the feetEnglish
The posture of a student before a teacher. Paul said he was brought up “at the feet of Gamaliel” (Acts 22:3).
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AthensEnglish
A famous city in ancient Greece.
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Atlantic OceanEnglish
The great ocean between Europe and Africa on one side and the Americas on the other.
Explore Travel and Faraway Places, Stop 3.4 (Ages 7–9) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 5.2 (grade 3)

Atlantic WallEnglish
Germany’s chain of coastal defenses from Norway to Spain: bunkers, guns, mines and beach obstacles.
Explore Great Battles · Expert, Stop 5.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.7 (Ages 10–13)

atlasEnglish
A bound book of maps. The word was first used this way for a collection by Gerard Mercator, published in 1595.
Explore Travel and Faraway Places · Expert, Stop 1.7 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 1.7 (Ages 10–13) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 1.4 (grade 2) · +1 more

atollEnglish
A ring-shaped coral reef or chain of low coral islands surrounding a lagoon, with deep ocean outside.
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attritionalEnglish
Built up gradually from animals dying one at a time over a long period, rather than all at once.
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“Auca”English
A Quichua word meaning “savage,” used by neighboring peoples and by outsiders for the Waodani in the 1950s. The Waodani call themselves Waodani, “the people.” This stop uses “Auca” only for the historical name of the mission.
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AucaEnglish
A name meaning “savage” in the Quichua language, once used by outsiders for the Waorani. Today it is not used for them.
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auctionEnglish
A public sale where buyers bid against each other and the highest bid wins.
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AugustaEnglish
The highest title for a woman of the Roman imperial family. Constantine gave it to his mother Helena in 324.
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AugustineEnglish
Monica’s son, who became a great Christian teacher and bishop of Hippo in North Africa.
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authorEnglish
The person who writes a book.
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author’s purposeEnglish
What a writer means a book to do: to inform, persuade, delight, or change behavior. Sewell said her aim was to change how people treated horses.
Explore Horses and Ponies · Expert, Stop 4.1 (Ages 14+)

autobiographical fictionEnglish
Stories based on an author’s own life but shaped as novels, with events moved, people combined or left out, and conversations invented.
Explore Heroines of History and Faith · Expert, Stop 3.8 (Ages 14+)

autobiographyEnglish
The story of a life told by the one who lived it. Black Beauty is a pretend autobiography: a horse tells his own story.
Explore Horses and Ponies · Ranger, Stop 4.1 (Ages 10–13) · Explore Horses and Ponies, Stop 4.1 (Ages 7–9)

average saleEnglish
Total sales ÷ number of buyers. It shows whether people buy one item or several.
Explore Crafts and Making · Expert, Stop 4.7 (Ages 14+)

awlEnglish
A sharp, pointed tool for piercing sewing holes through folded paper.
Explore Crafts and Making · Expert, Stop 3.7 (Ages 14+)

axolotlEnglish
A Mexican salamander that keeps its feathery gills and lives its whole life in water (say “AX-oh-LOT-ul”).
Explore Animals · Ranger, Stop 3.8 (Ages 10–13)

azhdarchidEnglish
A family of large, toothless pterosaurs with very long, stiff necks, long jaws and long legs. Quetzalcoatlus is the best-known member.
Explore Dinosaurs · Expert, Stop 5.5 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 5.5 (Ages 10–13)

azoic hypothesisEnglish
The idea, proposed by Edward Forbes in the 1840s, that no animals could live below about 300 fathoms (550 m); later disproved.
Explore Animals · Expert, Stop 4.7 (Ages 14+)

backstitchEnglish
A strong stitch in which each new stitch goes back to meet the end of the last, making a solid line on top and overlapping stitches beneath.
Explore Crafts and Making · Expert, Stop 1.3 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 1.3 (Ages 10–13) · Explore Crafts and Making, Stop 1.3 (Ages 7–9) · +1 more

backtackEnglish
A few stitches sewn in reverse at the start and end of a seam to lock it.
Explore Crafts and Making · Expert, Stop 1.8 (Ages 14+)

backward timelineEnglish
A schedule made by starting from the moment the party begins and working back, so each task is placed early enough to be finished on time.
Explore Hospitality and Home · Expert, Stop 3.8 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 1.8 (Ages 10–13)

badlandsEnglish
Dry, steep, deeply eroded country with little soil or plant cover, where fossils weather out of the rock.
Explore Dinosaurs · Expert, Stop 2.7 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 2.7 (Ages 10–13) · Explore Dinosaurs, Stop 2.6 (Ages 7–9)

bake saleEnglish
A sale of homemade baked goods, often to raise money for a good cause.
Explore Hospitality and Home, Stop 4.2 (Ages 7–9)

baleenEnglish
Long plates of a fingernail-like material (keratin) that hang from the upper jaw of some whales and strain small animals out of seawater.
Explore Animals · Expert, Stop 1.3 (Ages 14+) · Explore Animals · Ranger, Stop 1.3 (Ages 10–13) · Grade 1 Life Science: Animal Homes and Habits, Lesson 3.1 (grade 1) · +1 more

ballistic tongueEnglish
A tongue launched like a projectile, powered by stored elastic energy rather than by muscle pulling during the strike.
Explore Animals · Expert, Stop 3.5 (Ages 14+)

ballooningEnglish
Travel by air: a spider lets out silk threads that lift it on the wind and on the earth’s electric field.
Explore Animals · Expert, Stop 5.4 (Ages 14+)

band samplerEnglish
A long, narrow sampler of the 1600s with horizontal rows (bands) of repeating patterns, often kept rolled up in a workbasket for reference.
Explore Crafts and Making · Expert, Stop 2.6 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 2.6 (Ages 10–13)

banding (ringing)English
Placing a small numbered band on a bird’s leg so it can be identified if it is caught or found again.
Explore Animals · Expert, Stop 2.7 (Ages 14+)

bannerEnglish
A flag carried in front of an army.
Explore Great Battles, Stop 2.6 (Ages 7–9) · Explore Heroines of History and Faith, Stop 2.8 (Ages 7–9)

baptismEnglish
The Christian rite of washing with water in the name of the Father, the Son and the Holy Ghost, marking a person’s entrance into the church.
Explore Heroines of History and Faith · Ranger, Stop 3.4 (Ages 10–13)

bar scaleEnglish
A small ruler printed on a map, marked to show real distances.
Explore Travel and Faraway Places · Ranger, Stop 1.4 (Ages 10–13)

BarakEnglish
The army captain whom Deborah called to lead Israel.
Explore Heroines of History and Faith, Stop 1.3 (Ages 7–9)

baraminEnglish
A word coined by the creation biologist Frank Marsh in 1941 from the Hebrew bara (created) and min (kind): a group of living things descended from one original created kind.
Explore Dinosaurs · Expert, Stop 4.1 (Ages 14+) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 3.4 (grade 8)

baraminologyEnglish
The study, by creation biologists, of which living and fossil species belong to the same created kind (from Hebrew bara, “create,” and min, “kind”).
Explore Dinosaurs · Ranger, Stop 4.4 (Ages 10–13) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 3.4 (grade 8)

BarbEnglish
A hardy horse breed of North Africa’s Barbary Coast. Some writers of the 1700s called the Godolphin Arabian “the Godolphin Barb,” and his exact origin is debated.
Explore Horses and Ponies · Expert, Stop 4.6 (Ages 14+) · Grade 3 Life Science: Plants and Animals Together, Lesson 6.1 (grade 3)

barrageEnglish
A heavy, steady bombardment by many big guns at once, often moving forward ahead of attacking soldiers.
Explore Great Battles · Ranger, Stop 5.6 (Ages 10–13)

barrel racingEnglish
A timed rodeo event in which horse and rider run a cloverleaf pattern around three barrels as fast as possible.
Explore Horses and Ponies · Ranger, Stop 2.8 (Ages 10–13) · Explore Horses and Ponies, Stop 2.8 (Ages 7–9)

barrenEnglish
The Bible’s word for a woman unable to bear children. In the ancient world it touched a family’s name, land and future, not only its feelings.
Explore Heroines of History and Faith · Expert, Stop 1.1 (Ages 14+) · Explore Heroines of History and Faith, Stop 1.1 (Ages 7–9)

barrier islandEnglish
A long, narrow island of sand lying parallel to a mainland coast, shielding bays and marshes behind it from the open sea. Storms and currents constantly reshape it.
Explore Horses and Ponies · Expert, Stop 1.7 (Ages 14+) · Explore Horses and Ponies · Expert, Stop 4.4 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.7 (Ages 10–13) · +3 more

barrier reefEnglish
A reef that grows farther out from shore, with a lagoon between it and the land.
Explore Animals · Ranger, Stop 4.3 (Ages 10–13)

bars of the mouthEnglish
The toothless gums between a horse’s front teeth and its cheek teeth, where the bit rests.
Explore Horses and Ponies · Expert, Stop 2.2 (Ages 14+)

base colorEnglish
The coat color before any changes: black or chestnut (red), set by the extension gene. A horse with at least one dominant E can make black pigment; an ee horse is chestnut.
Explore Horses and Ponies · Expert, Stop 1.8 (Ages 14+)

base-4 notationEnglish
The way heights are written: hands, a point, then spare inches (0 to 3). 15.2 means 15 hands and 2 inches, or 62 inches; after 15.3 comes 16.0.
Explore Horses and Ponies · Expert, Stop 1.1 (Ages 14+)

basic settingEnglish
The simplest everyday setting: plate, fork, knife, spoon, glass and napkin.
Explore Hospitality and Home · Expert, Stop 2.2 (Ages 14+)

basilicaEnglish
A large Roman hall with a long central nave and side aisles; Constantine’s builders used this shape for the first great churches.
Explore Heroines of History and Faith · Expert, Stop 2.2 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.2 (Ages 10–13)

basis weight (gsm)English
The weight of paper, given in grams per square meter. Ordinary copy paper is about 75–90 gsm; card stock is about 200–300 gsm.
Explore Crafts and Making · Expert, Stop 3.4 (Ages 14+)

baskEnglish
To lie in the sun to soak up its warmth.
Explore Dinosaurs, Stop 3.6 (Ages 7–9) · Grade 1 Life Science: Animal Homes and Habits, Lesson 4.2 (grade 1) · Grade 2 Life Science: Animal Families, Lesson 3.1 (grade 2)

basteEnglish
To sew long, loose running stitches that hold cloth in place for a while and are taken out later.
Explore Crafts and Making · Ranger, Stop 1.3 (Ages 10–13)

bastilleEnglish
A wooden or earthen fort built by besiegers outside a city. The English ringed Orléans with bastilles but had too few men to close every gap.
Explore Great Battles · Expert, Stop 2.6 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.6 (Ages 10–13) · Explore Heroines of History and Faith · Ranger, Stop 2.8 (Ages 10–13)

bastingEnglish
Long, temporary running stitches that hold layers together before final sewing.
Explore Crafts and Making · Expert, Stop 1.3 (Ages 14+) · Home Décor, Costume & Upholstery, Lesson 5.4 (grade 9–12) · Textile Science & Clothing Construction, Lesson 8.4 (grade 9–12)

bastionEnglish
An arrow-shaped projection from a fortress wall, built so defenders can fire along the face of the wall at attackers from two sides.
Explore Great Battles · Expert, Stop 3.2 (Ages 14+)

batEnglish
A mammal with wings made of skin stretched over long finger bones.
Explore Animals, Stop 1.4 (Ages 7–9) · Explore Animals, Stop 6.1 (Ages 7–9) · Grade 2 Life Science: Animal Families, Lesson 1.2 (grade 2)

batch costEnglish
The total cost of all ingredients used in one batch of a recipe.
Explore Hospitality and Home · Expert, Stop 4.3 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 4.3 (Ages 10–13) · Explore Hospitality and Home, Stop 4.3 (Ages 7–9)

batch productionEnglish
Making several items at once, step by step, rather than one from start to finish. It saves set-up time on each item.
Explore Crafts and Making · Expert, Stop 4.3 (Ages 14+)

bathysphereEnglish
A hollow steel ball lowered on a cable to carry explorers into the deep sea.
Explore Animals · Ranger, Stop 4.7 (Ages 10–13)

batrachotoxinEnglish
An extremely powerful alkaloid in the skin of the golden poison frog and its relatives that holds sodium channels in nerves and muscles open.
Explore Animals · Expert, Stop 3.9 (Ages 14+)

battingEnglish
The soft middle layer of a quilt (cotton, wool or polyester) that traps air for warmth; older books call it wadding or filling.
Explore Crafts and Making · Expert, Stop 2.8 (Ages 14+) · Explore Crafts and Making, Stop 2.8 (Ages 7–9) · Fabrics & Sewing I, Lesson 7.3 (grade 3–5) · +1 more

Battle of Bunker HillEnglish
An early battle of the Revolution, fought on 17 June 1775 on the hills of Charlestown, across the river from Boston.
Explore Heroines of History and Faith · Ranger, Stop 3.6 (Ages 10–13)

Battle of GravelinesEnglish
The main battle of the campaign, fought off the Flemish coast on 29 July 1588 (Old Style), the day after the fireship attack.
Explore Heroines of History and Faith · Expert, Stop 3.3 (Ages 14+)

bayonetEnglish
A long blade fixed to the end of a rifle.
Explore Great Battles, Stop 4.7 (Ages 7–9)

bayouEnglish
A slow, marshy stream in the low country of Louisiana and the Gulf Coast.
Explore Great Battles · Ranger, Stop 4.2 (Ages 10–13)

beaconEnglish
A fire lit on a hilltop to send a warning quickly from hill to hill across the country.
Explore Heroines of History and Faith · Ranger, Stop 3.3 (Ages 10–13)

beadEnglish
A small object pierced for stringing. The word comes from Old English gebed, “prayer,” because strings of beads were used to count prayers; the name moved from the prayer to the bead.
Explore Crafts and Making · Expert, Stop 3.8 (Ages 14+) · Explore Crafts and Making, Stop 3.8 (Ages 7–9)

beakEnglish
A hard, toothless mouth edge, like a parrot’s.
Explore Dinosaurs, Stop 1.2 (Ages 7–9) · Grade 2 Gardening & Animals, Lesson 2.1 (grade 2) · Kindergarten Gardening & Animals, Lesson 2.2 (grade K) · +3 more

bearing reinEnglish
A strap running from the bit up to a hook on the harness that holds a carriage horse’s head high. Americans usually called it a check-rein.
Explore Horses and Ponies · Expert, Stop 4.2 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 4.2 (Ages 10–13) · Explore Horses and Ponies, Stop 4.2 (Ages 7–9)

beast of the earthEnglish
The KJV phrase in Genesis 1:24–25 for wild land animals, made on the sixth day along with cattle and creeping things.
Explore Dinosaurs · Ranger, Stop 4.1 (Ages 10–13)

beast of the earth (Hebrew chayyah)English
In Genesis 1:24–25, wild land animals, as distinct from “cattle” (Hebrew behemah, larger tame-type beasts) and “creeping things” (Hebrew remes, small animals that move low to the ground).
Explore Dinosaurs · Expert, Stop 4.1 (Ages 14+)

bed-and-breakfastEnglish
A private home, or a small inn run like one, that rents a few rooms for the night and serves breakfast in the morning.
Explore Hospitality and Home · Expert, Stop 4.5 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 4.5 (Ages 10–13) · Explore Hospitality and Home, Stop 4.5 (Ages 7–9)

BedeEnglish
A monk of Jarrow, called the Venerable Bede, who finished his Ecclesiastical History of the English People in 731.
Explore Heroines of History and Faith · Ranger, Stop 2.5 (Ages 10–13) · Explore Heroines of History and Faith, Stop 2.5 (Ages 7–9)

BedouinEnglish
The nomadic Arab tribes of the deserts of Arabia and Syria, who lived by camels, goats and horses and moved between wells and seasonal grazing.
Explore Horses and Ponies · Expert, Stop 1.2 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.2 (Ages 10–13) · Explore Horses and Ponies, Stop 1.2 (Ages 7–9) · +1 more

bee spaceEnglish
A gap of about a quarter to three-eighths of an inch (6–9 mm) that bees leave open as a walkway. Smaller gaps they seal; larger ones they fill with comb.
Explore Animals · Expert, Stop 5.2 (Ages 14+) · Grade 5 Gardening & Animals, Lesson 6.4 (grade 5)

beetleEnglish
An insect with a pair of hard wing covers that close over its flying wings.
Explore Animals, Stop 5.5 (Ages 7–9) · Grade 3 Life Science: Plants and Animals Together, Lesson 6.4 (grade 3) · Kindergarten Life Science: God Made the Animals, Lesson 4.3 (grade K)

Belgian neutralityEnglish
Belgium’s status, guaranteed by the great powers in the Treaty of London (1839), as a country no army may march through. Germany’s invasion of Belgium brought Britain into the war.
Explore Great Battles · Expert, Stop 5.1 (Ages 14+)

BelialEnglish
A Hebrew word meaning “worthlessness.” “A son of Belial” or “man of Belial” describes a wicked, good-for-nothing person.
Explore Heroines of History and Faith · Expert, Stop 1.6 (Ages 14+)

bellEnglish
The round, umbrella-shaped top of a jellyfish.
Explore Animals, Stop 4.6 (Ages 7–9)

belly scalesEnglish
The wide scales under a snake that grip the ground and help it move.
Explore Animals, Stop 3.3 (Ages 7–9) · Grade 2 Life Science: Animal Families, Lesson 3.2 (grade 2)

Belmont StakesEnglish
The third and longest Triple Crown race, 1 1/2 miles, run at Belmont Park near New York City.
Explore Horses and Ponies · Ranger, Stop 3.8 (Ages 10–13)

BenediciteEnglish
Latin, “Bless ye,” the opening word of a traditional prayer before meals. Chardin’s painting Le Bénédicité takes its title from it.
Explore Hospitality and Home · Expert, Stop 2.5 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.5 (Ages 10–13)

BeowulfEnglish
A very old English poem about a hero who fights monsters and, at the end, a dragon (say “BAY-uh-wulf”).
Explore Dinosaurs, Stop 4.6 (Ages 7–9)

Berlin woolworkEnglish
A craze of the 1800s for stitching colored wool on canvas from hand-colored printed charts, first published in Berlin early in the century.
Explore Crafts and Making · Expert, Stop 2.7 (Ages 14+)

BethanyEnglish
A village on the Mount of Olives, “about fifteen furlongs” (roughly 1.7 miles) from Jerusalem (John 11:18), home of Martha, Mary and Lazarus.
Explore Hospitality and Home · Expert, Stop 3.3 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 3.3 (Ages 10–13) · Explore Hospitality and Home, Stop 3.3 (Ages 7–9)

BethlehemEnglish
A small town about 6 miles south of Jerusalem, where Jesus was born.
Explore Travel and Faraway Places, Stop 4.1 (Ages 7–9)

betrothalEnglish
In first-century Judaism, a binding agreement to marry, made before the couple lived together. Breaking it required a formal divorce (Matthew 1:19).
Explore Heroines of History and Faith · Expert, Stop 1.8 (Ages 14+)

biddenEnglish
In the KJV, invited. “Them that were bidden” are the invited guests.
Explore Hospitality and Home · Expert, Stop 3.4 (Ages 14+)

Big Bend National ParkEnglish
A desert park in Texas along the Rio Grande river, where Quetzalcoatlus was found.
Explore Dinosaurs, Stop 5.5 (Ages 7–9)

bind offEnglish
To finish a piece by lifting each stitch over the next so the last row is locked and will not unravel.
Explore Crafts and Making · Ranger, Stop 2.4 (Ages 10–13) · Explore Crafts and Making, Stop 2.4 (Ages 7–9)

bind off (cast off)English
To finish the work by knitting two stitches and lifting the first over the second, again and again, so the loops cannot unravel.
Explore Crafts and Making · Expert, Stop 2.3 (Ages 14+)

bindingEnglish
A strip of fabric folded over and sewn around the raw edges of a finished quilt.
Explore Crafts and Making · Expert, Stop 2.8 (Ages 14+) · Fabrics & Sewing II, Lesson 7.3 (grade 6–8) · Home Décor, Costume & Upholstery, Lesson 5.5 (grade 9–12)

binding offEnglish
Finishing the knitting by passing each loop through the next so the work cannot unravel.
Explore Crafts and Making · Ranger, Stop 2.2 (Ages 10–13)

binocular visionEnglish
Sight in which both eyes see the same area at once, which lets an animal judge distance.
Explore Dinosaurs · Expert, Stop 1.1 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.1 (Ages 10–13)

binomial nameEnglish
A two-part scientific name, genus and species, such as Castor canadensis for the North American beaver; the genus is capitalized and both words are italicized.
Explore Animals · Expert, Stop 6.10 (Ages 14+) · Explore Animals · Ranger, Stop 6.10 (Ages 10–13)

biofilmEnglish
A slimy film made by colonies of bacteria. Critics suggested the vessel-like structures might be biofilm rather than original tissue.
Explore Dinosaurs · Expert, Stop 2.10 (Ages 14+) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 5.2 (grade 8)

biological controlEnglish
Using a pest’s natural enemies, such as a predatory beetle, to keep the pest in check.
Explore Animals · Expert, Stop 5.5 (Ages 14+)

bioluminescenceEnglish
Light made by living things through a chemical reaction. In the deep sea it is the main source of light.
Explore Animals · Expert, Stop 4.4 (Ages 14+) · Explore Animals · Expert, Stop 4.7 (Ages 14+) · Explore Animals · Expert, Stop 5.6 (Ages 14+) · +3 more

biomagnificationEnglish
The increase in concentration of a long-lasting chemical at each higher step of a food chain.
Explore Animals · Expert, Stop 2.1 (Ages 14+)

biomechanicsEnglish
The study of how living bodies move, using the laws of physics and engineering.
Explore Dinosaurs · Expert, Stop 3.5 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 3.5 (Ages 10–13)

biomimeticsEnglish
Engineering that copies principles found in living things; the word was coined in the 1950s by the American engineer Otto Schmitt.
Explore Animals · Expert, Stop 6.9 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 4.10 (Ages 10–13)

biomimicryEnglish
Copying a design found in living things to solve a human problem.
Explore Animals · Ranger, Stop 5.5 (Ages 10–13) · Explore Animals · Ranger, Stop 6.9 (Ages 10–13) · Grade 6 Life Science: Animal Design and Behavior, Lesson 8.1 (grade 6)

birdEnglish
An animal with feathers, wings and a beak that lays eggs with hard shells.
Explore Animals, Stop 2.1 (Ages 7–9) · Grade 2 Life Science: Animal Families, Lesson 2.1 (grade 2)

bird bandingEnglish
Putting a small marked band on a bird’s leg to learn where it goes.
Explore Animals, Stop 2.9 (Ages 7–9) · Grade 8 Gardening & Animals, Lesson 2.3 (grade 8) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 8.2 (grade 8)

bird countEnglish
Counting the birds in one place for a set time, so scientists know how many there are.
Explore Animals, Stop 2.10 (Ages 7–9)

bird of preyEnglish
A bird that hunts other animals with its feet and hooked beak, such as an eagle, hawk or owl.
Explore Animals, Stop 2.1 (Ages 7–9) · Grade 2 Life Science: Animal Families, Lesson 2.2 (grade 2)

Birtwick ParkEnglish
Black Beauty’s first good home, with Squire Gordon.
Explore Horses and Ponies, Stop 4.2 (Ages 7–9)

bishop’s mitreEnglish
A standing napkin fold shaped like the tall, pointed hat worn by bishops in many churches.
Explore Hospitality and Home · Expert, Stop 2.3 (Ages 14+)

bisonEnglish
A large, shaggy wild ox of North America and Europe; Americans often call it “buffalo.”
Explore Animals · Ranger, Stop 1.10 (Ages 10–13) · Explore Animals, Stop 1.10 (Ages 7–9) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.2 (grade 2) · +2 more

Bison bisonEnglish
The scientific name of the American bison, the largest land mammal in North America. Americans have long called it the buffalo.
Explore Animals · Expert, Stop 1.10 (Ages 14+)

bite forceEnglish
The pushing force of a closing jaw, measured in newtons (N). For extinct animals it is estimated from computer models of the skull and jaw muscles.
Explore Dinosaurs · Expert, Stop 1.1 (Ages 14+)

Black CloisterEnglish
The former Augustinian friary in Wittenberg where Luther had lived as a monk. The Elector of Saxony gave it to the Luthers, and it became their home, boarding house and guest house.
Explore Heroines of History and Faith · Expert, Stop 3.1 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 3.1 (Ages 10–13) · Explore Heroines of History and Faith, Stop 3.1 (Ages 7–9)

blastemaEnglish
A cluster of unspecialized cells that forms at the stump of a lost limb and grows into the new limb.
Explore Animals · Expert, Stop 3.8 (Ages 14+)

blazeEnglish
A wide white stripe running down the face from the forehead to the nose.
Explore Horses and Ponies · Ranger, Stop 1.8 (Ages 10–13) · Explore Horses and Ponies, Stop 1.8 (Ages 7–9)

blindEnglish
Unable to see.
Explore Heroines of History and Faith, Stop 4.4 (Ages 7–9)

blind bakeEnglish
To bake an empty crust before filling it, weighed down so it keeps its shape.
Explore Hospitality and Home · Ranger, Stop 1.7 (Ages 10–13)

blind bakingEnglish
Baking an empty pie shell, lined with parchment and weighed down with pie weights or dried beans, before adding a filling, so the bottom does not turn soggy.
Explore Hospitality and Home · Expert, Stop 1.7 (Ages 14+)

blind spotEnglish
The areas a horse cannot see: a narrow zone directly behind it and a small patch directly in front of and below its nose.
Explore Horses and Ponies · Expert, Stop 2.7 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.7 (Ages 10–13) · Explore Horses and Ponies, Stop 2.7 (Ages 7–9)

BlitzkriegEnglish
“Lightning war”: a name for fast German attacks that concentrated tanks and dive bombers on a narrow front, then drove deep behind the enemy.
Explore Great Battles · Expert, Stop 5.3 (Ages 14+)

blockadeEnglish
The use of warships to close an enemy’s ports so that no ships can enter or leave. Lincoln proclaimed a blockade of the Confederate coast in April 1861.
Explore Great Battles · Expert, Stop 4.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 4.5 (Ages 10–13) · Explore Great Battles, Stop 4.5 (Ages 7–9) · +1 more

blood pressureEnglish
The pressure the heart puts on the blood, measured in millimeters of mercury (mmHg). It must be high enough to push blood up to the brain.
Explore Dinosaurs · Expert, Stop 1.4 (Ages 14+) · Explore Dinosaurs · Expert, Stop 3.9 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 3.9 (Ages 10–13) · +2 more

bloodguiltEnglish
The guilt of shedding innocent blood. Abigail warned that killing Nabal’s household would stain David’s conscience and his future reign.
Explore Heroines of History and Faith · Expert, Stop 1.6 (Ages 14+)

blotterEnglish
Thick, absorbent paper (or newspaper, or plain paper towels) placed on both sides of a plant in the press to draw out water.
Explore Crafts and Making · Expert, Stop 3.6 (Ages 14+)

blotting paperEnglish
Soft, thick, absorbent paper that draws water out of flowers as they press.
Explore Crafts and Making · Ranger, Stop 3.6 (Ages 10–13) · Grade 4 Life Science: Classification, Lesson 6.4 (grade 4)

blowholeEnglish
A whale’s nostril, set on top of the head so it can breathe at the surface without lifting its head. Baleen whales have two; toothed whales have one.
Explore Animals · Expert, Stop 1.3 (Ages 14+) · Explore Animals · Ranger, Stop 1.3 (Ages 10–13) · Explore Animals · Ranger, Stop 4.5 (Ages 10–13) · +3 more

blubberEnglish
A thick layer of fat under a whale’s skin that keeps it warm and stores energy.
Explore Animals · Ranger, Stop 1.3 (Ages 10–13) · Explore Animals · Ranger, Stop 2.4 (Ages 10–13) · Explore Animals · Ranger, Stop 4.5 (Ages 10–13) · +3 more

Blue LiasEnglish
The layered grey limestone and shale of the cliffs around Lyme Regis, rich in ammonites and marine reptiles. Museums label it “Early Jurassic.”
Explore Dinosaurs · Expert, Stop 2.1 (Ages 14+)

bluffEnglish
A high, steep bank above a river. Vicksburg stood on bluffs about 200 feet above the Mississippi.
Explore Great Battles · Expert, Stop 4.6 (Ages 14+) · Explore Great Battles · Ranger, Stop 4.6 (Ages 10–13) · Explore Great Battles, Stop 4.6 (Ages 7–9) · +1 more

boardingEnglish
Fighting by bringing two ships together and sending soldiers across onto the enemy deck. Most of the fighting at Lepanto was decided this way.
Explore Great Battles · Expert, Stop 2.8 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.8 (Ages 10–13)

bobbinEnglish
A small spool under the needle plate that holds the lower thread.
Explore Crafts and Making · Expert, Stop 1.8 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 1.8 (Ages 10–13) · Explore Crafts and Making, Stop 1.8 (Ages 7–9) · +2 more

bodkinEnglish
A blunt, large-eyed tool, or a safety pin, used to pull cord or elastic through a casing.
Explore Crafts and Making · Expert, Stop 1.6 (Ages 14+)

body brushEnglish
A soft, dense brush that removes fine dust and spreads the skin’s natural oils; used on the face, legs and the whole coat to finish.
Explore Horses and Ponies · Expert, Stop 2.3 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.3 (Ages 10–13) · Explore Horses and Ponies, Stop 2.3 (Ages 7–9)

body condition scoreEnglish
A 1-to-9 scale (the Henneke scale) for judging fat cover by eye and touch; about 5 is ideal, with ribs easily felt but not seen.
Explore Horses and Ponies · Expert, Stop 2.5 (Ages 14+) · Grade 6 Gardening & Animals, Lesson 4.2 (grade 6) · Grade 6 Gardening & Animals, Lesson 6.3 (grade 6)

bogEnglish
Soft, wet, muddy ground where horses sink.
Explore Great Battles, Stop 2.4 (Ages 7–9)

bombardEnglish
A very large early cannon that fired great stone balls. Mehmed’s largest, cast by the founder Urban, could fire only a few times a day.
Explore Great Battles · Expert, Stop 2.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.7 (Ages 10–13) · Geography and History: Why Borders Fall Where They Do, Lesson 6.1 (grade 9–12)

bombardier beetleEnglish
A beetle that mixes two chemicals in a chamber in its body and sprays a hot, irritating jet, close to boiling, at attackers.
Explore Dinosaurs · Expert, Stop 4.3 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 4.3 (Ages 10–13)

bone densityEnglish
How solid a bone is. Dense, heavy bones help animals such as penguins and hippos stay under water.
Explore Dinosaurs · Expert, Stop 1.7 (Ages 14+)

bone folderEnglish
A smooth, flat tool, once made of bone, used to press sharp creases in paper.
Explore Crafts and Making · Ranger, Stop 3.7 (Ages 10–13)

bone histologyEnglish
The study of the microscopic structure of bone tissue in thin slices.
Explore Dinosaurs · Expert, Stop 3.8 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 3.6 (Ages 10–13)

Bone WarsEnglish
The bitter competition, roughly 1868–1890s, between paleontologists E. D. Cope of Philadelphia and O. C. Marsh of Yale to find and name new fossil animals in the American West.
Explore Dinosaurs · Expert, Stop 2.6 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 2.6 (Ages 10–13)

bonebedEnglish
A layer of rock containing the bones of many individual animals, often of one species.
Explore Dinosaurs · Expert, Stop 3.4 (Ages 14+) · Explore Dinosaurs · Expert, Stop 4.5 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 3.4 (Ages 10–13) · +2 more

bookbinderEnglish
A craftsman who sews or glues pages together and puts a cover on them.
Explore Crafts and Making, Stop 3.7 (Ages 7–9)

boom and bustEnglish
A rapid rise in a business or price followed by a sudden collapse, as in the ostrich-feather trade before and after 1914.
Explore Animals · Expert, Stop 2.5 (Ages 14+)

Boston Tea PartyEnglish
The protest of 16 December 1773, in which colonists destroyed 342 chests of East India Company tea in Boston Harbor in opposition to the Tea Act and taxation by Parliament.
Explore Hospitality and Home · Expert, Stop 2.8 (Ages 14+)

bottomEnglish
An old horseman’s word for stamina and toughness: the ability to keep going when tired.
Explore Horses and Ponies · Expert, Stop 3.3 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 3.3 (Ages 10–13)

brachiopatagiumEnglish
The main wing membrane, stretched from the tip of the wing finger to the body and hind limb, stiffened by fine fibers called actinofibrils.
Explore Dinosaurs · Expert, Stop 5.4 (Ages 14+)

bradycardiaEnglish
Slowing of the heartbeat. Diving seals slow the heart sharply to save oxygen.
Explore Animals · Expert, Stop 4.9 (Ages 14+)

BraintreeEnglish
The Massachusetts farming town south of Boston where the Adamses lived. The part where their farm stood later became the town of Quincy.
Explore Heroines of History and Faith · Expert, Stop 3.6 (Ages 14+) · Explore Heroines of History and Faith, Stop 3.6 (Ages 7–9)

bread plateEnglish
A small plate set above the forks, at the upper left of the place, often with a butter knife laid across it.
Explore Hospitality and Home · Expert, Stop 2.1 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.1 (Ages 10–13) · Explore Hospitality and Home, Stop 2.2 (Ages 7–9)

bread-and-butter letterEnglish
A traditional name for the thank-you note a guest writes to a host after a meal or a stay in the home.
Explore Hospitality and Home · Expert, Stop 3.7 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 3.7 (Ages 10–13)

breaking the lineEnglish
Sailing through a gap in the enemy’s line to cut it in pieces and fight part of it with superior numbers.
Explore Great Battles · Expert, Stop 3.8 (Ages 14+) · Tactics & Strategy, Lesson 5.4 (grade 4–7) · Tactics & Strategy, Lesson 4.3 (grade 8–12)

breedEnglish
A group of dogs (or other domestic animals) selected by people over many generations for a particular look or skill.
Explore Animals · Expert, Stop 1.6 (Ages 14+) · Explore Animals · Ranger, Stop 1.5 (Ages 10–13) · Explore Animals, Stop 1.6 (Ages 7–9) · +3 more

breeding programEnglish
A careful plan to raise young animals in safety and return them to the wild to help a rare animal recover.
Explore Animals · Ranger, Stop 3.6 (Ages 10–13) · Explore Animals, Stop 3.6 (Ages 7–9)

bridleEnglish
The headgear used for riding, made of straps, a bit and reins, used to guide the horse.
Explore Horses and Ponies · Ranger, Stop 2.2 (Ages 10–13) · Explore Horses and Ponies, Stop 2.2 (Ages 7–9)

British Expeditionary Force (BEF)English
The small professional British army sent to France in August 1914, about 100,000 men at first.
Explore Great Battles · Expert, Stop 5.1 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.1 (Ages 10–13)

broad-edge penEnglish
A pen with a flat, chisel-shaped tip. Held at a steady angle, it makes thick and thin strokes on its own.
Explore Crafts and Making · Ranger, Stop 3.3 (Ages 10–13)

brochureEnglish
A small folded paper that tells about a place.
Explore Hospitality and Home, Stop 4.6 (Ages 7–9)

bromeliadEnglish
A rainforest plant (a cousin of the pineapple) whose stiff leaves hold small pools of water, where some frogs raise tadpoles.
Explore Animals · Ranger, Stop 3.9 (Ages 10–13)

broodEnglish
To sit on eggs and keep them warm, as a hen does.
Explore Dinosaurs, Stop 3.2 (Ages 7–9) · Grade 5 Gardening & Animals, Lesson 6.4 (grade 5) · Grade 7 Gardening & Animals, Lesson 6.4 (grade 7)

brood cellEnglish
One chamber in a nest tube holding a ball of pollen and nectar with a single egg, sealed off from the next cell.
Explore Animals · Expert, Stop 5.10 (Ages 14+)

brood parasiteEnglish
A bird that lays its eggs in other birds’ nests and builds none of its own, such as the brown-headed cowbird.
Explore Animals · Expert, Stop 2.8 (Ages 14+)

brood patchEnglish
A patch of bare skin, rich in blood vessels, that develops on a parent bird’s belly so it can warm eggs directly.
Explore Animals · Expert, Stop 2.8 (Ages 14+) · Explore Animals · Ranger, Stop 2.8 (Ages 10–13)

brood pouchEnglish
A fold of feathered skin on the lower belly of emperor and king penguins that covers the egg as it rests on the parent’s feet.
Explore Animals · Expert, Stop 2.4 (Ages 14+) · Explore Animals · Ranger, Stop 2.4 (Ages 10–13)

brothEnglish
The flavored liquid of a soup.
Explore Hospitality and Home, Stop 1.5 (Ages 7–9)

brumationEnglish
The winter dormancy of reptiles such as snakes and turtles, whose body temperature follows their surroundings.
Explore Animals · Expert, Stop 6.3 (Ages 14+) · Explore Animals · Ranger, Stop 6.3 (Ages 10–13)

BsalEnglish
Short for Batrachochytrium salamandrivorans (“salamander-eating”), a chytrid fungus discovered in 2013 that kills many salamanders and newts.
Explore Animals · Expert, Stop 3.8 (Ages 14+)

BucephalaEnglish
The city Alexander founded on the Hydaspes (Jhelum) River, in what is now Pakistan, in memory of his horse.
Explore Horses and Ponies · Expert, Stop 3.1 (Ages 14+)

BucephalusEnglish
Alexander’s war horse. The name means “ox-head” in Greek (say “byoo-SEF-uh-lus”).
Explore Horses and Ponies · Ranger, Stop 3.1 (Ages 10–13) · Explore Horses and Ponies, Stop 3.1 (Ages 7–9)

buddy systemEnglish
Pairing travelers so that each is responsible for knowing where the other is at all times.
Explore Travel and Faraway Places · Expert, Stop 2.8 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.8 (Ages 10–13) · Explore Travel and Faraway Places, Stop 2.8 (Ages 7–9)

bufferEnglish
Spare time deliberately left between activities or connections to absorb delays.
Explore Travel and Faraway Places · Expert, Stop 2.4 (Ages 14+) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 7.4 (grade 8)

buffer timeEnglish
Extra time left in a plan for delays, rest or surprises.
Explore Travel and Faraway Places · Ranger, Stop 2.4 (Ages 10–13)

buffetEnglish
A meal set out on a side table where guests walk along and serve themselves (say “buh-FAY”).
Explore Hospitality and Home · Ranger, Stop 2.7 (Ages 10–13)

bundle priceEnglish
A lower price per item for buying several together, such as “3 for $1.25.”
Explore Hospitality and Home · Expert, Stop 4.4 (Ages 14+)

BurgundiansEnglish
The party of the Duke of Burgundy, allied with England in the 1420s; Burgundian soldiers captured Joan at Compiègne in 1430 and sold her to the English.
Explore Great Battles · Expert, Stop 2.6 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.6 (Ages 10–13)

burnEnglish
A Scots word for a stream. The Bannock Burn, with steep banks in places, ran across the English line of march and behind their camp.
Explore Great Battles · Expert, Stop 2.4 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.4 (Ages 10–13) · Explore Great Battles, Stop 2.4 (Ages 7–9)

burrEnglish
A prickly seed case that sticks to fur and clothes.
Explore Animals, Stop 6.9 (Ages 7–9) · Grade 4 Gardening & Animals, Lesson 5.3 (grade 4) · Grade 3 Life Science: Plants and Animals Together, Lesson 2.2 (grade 3) · +1 more

burrowEnglish
A hole or tunnel in the ground where an animal shelters.
Explore Animals · Ranger, Stop 3.10 (Ages 10–13) · Explore Animals, Stop 3.10 (Ages 7–9) · Explore Animals, Stop 6.3 (Ages 7–9) · +3 more

buttonEnglish
A small round piece that fastens clothes by slipping through a buttonhole.
Explore Crafts and Making, Stop 1.4 (Ages 7–9) · Threads & Weaving, Lesson 3.3 (grade 9–12)

buttonholeEnglish
A reinforced slit through which a button passes; its length is about the button’s diameter plus its thickness.
Explore Crafts and Making · Expert, Stop 1.4 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 1.4 (Ages 10–13) · Explore Crafts and Making, Stop 1.4 (Ages 7–9) · +1 more

buyback foalEnglish
A foal bought at auction and given back to the fire company so it can return to live wild on Assateague.
Explore Horses and Ponies · Ranger, Stop 4.5 (Ages 10–13)

buy-back ponyEnglish
A foal bought at auction and then given back to the fire company to return to the wild herd, keeping it healthy and its numbers steady.
Explore Horses and Ponies · Expert, Stop 4.5 (Ages 14+)

Byzantine EmpireEnglish
The name historians give to the Roman Empire in the East, ruled from Constantinople from 330 until 1453. Its people called themselves Romans.
Explore Great Battles · Expert, Stop 2.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.7 (Ages 10–13)

calcium carbonateEnglish
The mineral of limestone, chalk and seashells. Coral polyps take it from seawater to build their stony cups.
Explore Animals · Expert, Stop 4.3 (Ages 14+)

calculated riskEnglish
Nimitz’s instruction to his admirals: accept danger only when the damage you can do to the enemy is greater than the damage you are likely to suffer.
Explore Great Battles · Expert, Stop 5.5 (Ages 14+)

calfEnglish
A baby dolphin or whale.
Explore Animals, Stop 4.5 (Ages 7–9) · Kindergarten Gardening & Animals, Lesson 6.3 (grade K) · Grade 1 Life Science: Animal Homes and Habits, Lesson 3.1 (grade 1) · +2 more

caliphateEnglish
A state ruled by a caliph, a successor of Muhammad as leader of the Muslim community. The Umayyad Caliphate ruled from Damascus, from Spain to Central Asia.
Explore Great Battles · Ranger, Stop 2.1 (Ages 10–13)

Camellia sinensisEnglish
The tea plant, an evergreen shrub native to China and nearby regions. Black, green and oolong teas all come from its leaves, processed differently.
Explore Hospitality and Home · Expert, Stop 2.8 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.8 (Ages 10–13)

camouflageEnglish
Coloring, pattern, shape or behavior that keeps an animal from being noticed or recognized.
Explore Animals · Expert, Stop 6.2 (Ages 14+) · Explore Animals · Ranger, Stop 6.2 (Ages 10–13) · Explore Animals, Stop 3.5 (Ages 7–9) · +3 more

CanaanEnglish
The land God promised to Abraham and his children, later called Israel.
Explore Great Battles, Stop 1.8 (Ages 7–9) · Explore Heroines of History and Faith · Ranger, Stop 1.1 (Ages 10–13) · Explore Travel and Faraway Places · Expert, Stop 3.1 (Ages 14+) · +2 more

canine shear-biteEnglish
The leading idea for how Smilodon killed: holding prey still with its forelimbs, then driving the sabers in with powerful neck muscles.
Explore Dinosaurs · Expert, Stop 5.7 (Ages 14+)

canine toothEnglish
A long pointed tooth near the front of the mouth, used for gripping or stabbing. Dogs, cats and people all have canines.
Explore Dinosaurs · Ranger, Stop 5.7 (Ages 10–13) · Explore Dinosaurs, Stop 5.7 (Ages 7–9)

Canis lupusEnglish
The scientific name of the gray wolf. Many scientists name the dog Canis lupus familiaris, a form of the same species; others call it Canis familiaris.
Explore Animals · Expert, Stop 1.6 (Ages 14+)

cannonEnglish
A large gun that fires heavy balls of stone or iron.
Explore Great Battles, Stop 2.7 (Ages 7–9)

cannonadeEnglish
A long, heavy firing of many cannon at once.
Explore Great Battles · Ranger, Stop 4.7 (Ages 10–13)

canterEnglish
A three-beat gait, smooth and rocking.
Explore Horses and Ponies, Stop 2.6 (Ages 7–9)

canticleEnglish
A song from the Bible, other than a psalm, used in worship. The Magnificat has been sung at evening prayer in churches for well over a thousand years.
Explore Heroines of History and Faith · Expert, Stop 1.8 (Ages 14+)

cantonEnglish
One of the 26 states that make up the Swiss Confederation. Switzerland traces its founding to a league of three cantons, Uri, Schwyz and Unterwalden, in 1291.
Explore Travel and Faraway Places · Expert, Stop 4.5 (Ages 14+)

capitulationEnglish
A surrender on agreed terms, written as numbered articles.
Explore Great Battles · Expert, Stop 3.7 (Ages 14+)

capsule wardrobeEnglish
A small set of clothes in colors that all go together, so every top matches every bottom.
Explore Travel and Faraway Places · Expert, Stop 2.5 (Ages 14+)

captiveEnglish
A person who is held prisoner.
Explore Great Battles, Stop 2.8 (Ages 7–9)

captive breedingEnglish
Raising animals under human care, either for pets (so wild birds are not taken) or to restore rare species.
Explore Animals · Expert, Stop 2.6 (Ages 14+) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 7.3 (grade 8)

captive breeding and repatriationEnglish
Raising young animals in protected pens and then returning them to the wild places their kind once lived.
Explore Animals · Expert, Stop 3.6 (Ages 14+)

carapaceEnglish
The top part of a turtle's shell. The bottom part is the plastron.
Explore Animals · Ranger, Stop 3.4 (Ages 10–13) · Grade 4 Life Science: Classification, Lesson 3.2 (grade 4)

carapace and plastronEnglish
The upper shell (carapace) and lower shell (plastron) of a turtle. Both are bone, fused with the ribs and backbone, and covered with horny plates called scutes.
Explore Animals · Expert, Stop 3.4 (Ages 14+)

caravanseraiEnglish
A walled roadside inn of the Near East and Central Asia, built around a courtyard where travelers and their animals stayed overnight.
Explore Hospitality and Home · Expert, Stop 4.5 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 4.5 (Ages 10–13) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 1.2 (grade 9–12) · +2 more

caravelEnglish
A small, nimble Portuguese and Spanish sailing ship of the 1400s; the Niña and Pinta were caravels, while the larger Santa María was a nao (carrack).
Explore Travel and Faraway Places · Expert, Stop 3.4 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.4 (Ages 10–13) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 6.3 (grade 3) · +2 more

cardenolidesEnglish
Bitter heart poisons in milkweed sap. Monarch caterpillars store them, which makes both caterpillars and adults distasteful or sickening to birds.
Explore Animals · Expert, Stop 5.3 (Ages 14+)

cardinal directionsEnglish
The four main directions: north, east, south and west. “Cardinal” comes from the Latin cardo, a hinge: the directions the rest turn on.
Explore Travel and Faraway Places · Expert, Stop 1.2 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 1.2 (Ages 10–13) · Explore Travel and Faraway Places, Stop 1.2 (Ages 7–9) · +1 more

cardingEnglish
Brushing clean wool between two toothed paddles (cards) so the fibers lie loose and in the same direction.
Explore Crafts and Making · Ranger, Stop 2.1 (Ages 10–13) · Explore Crafts and Making, Stop 2.1 (Ages 7–9) · Grade 3 Gardening & Animals, Lesson 6.3 (grade 3) · +1 more

cardstockEnglish
Thick, stiff paper used for cards. In the United States it is often sold as 65 lb or 110 lb “cover” stock; elsewhere by grams per square meter (gsm).
Explore Crafts and Making · Ranger, Stop 3.4 (Ages 10–13)

carefulEnglish
In the KJV, “full of care”: anxious and worried. It does not mean “cautious,” as it does today.
Explore Hospitality and Home · Expert, Stop 3.3 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 3.3 (Ages 10–13) · Explore Hospitality and Home, Stop 3.3 (Ages 7–9)

CarmelEnglish
A town in Judah where Nabal kept his sheep.
Explore Heroines of History and Faith, Stop 1.6 (Ages 7–9)

carnivoreEnglish
An animal that eats meat.
Explore Dinosaurs · Ranger, Stop 3.1 (Ages 10–13) · Explore Dinosaurs, Stop 3.1 (Ages 7–9) · Grade 2 Gardening & Animals, Lesson 4.3 (grade 2) · +3 more

CarolingianEnglish
The family of Charles Martel, named from the Latin Carolus (Charles). It included his son Pepin the Short, the first Carolingian king, and his grandson Charlemagne.
Explore Great Battles · Expert, Stop 2.1 (Ages 14+)

carotenoidsEnglish
The pigments of yellow and orange flowers (and carrots). They are more stable than anthocyanins, so yellows usually keep their color well.
Explore Crafts and Making · Expert, Stop 3.6 (Ages 14+)

carrionEnglish
The flesh of dead animals. Komodo dragons eat both live prey and carrion.
Explore Animals · Ranger, Stop 3.2 (Ages 10–13)

carry-onEnglish
A bag taken into the cabin of a plane or train and kept with you; most U.S. airlines allow about 22 × 14 × 9 inches plus a small personal item.
Explore Travel and Faraway Places · Expert, Stop 2.5 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.5 (Ages 10–13) · Explore Travel and Faraway Places, Stop 2.5 (Ages 7–9)

carseEnglish
A Scots word for low, flat, wet land beside a river. The carse below Stirling, cut by streams and pools, was where the English camped the night before the battle.
Explore Great Battles · Expert, Stop 2.4 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.4 (Ages 10–13)

CarthageEnglish
A great city in North Africa, in what is now Tunisia, and Rome’s rival.
Explore Great Battles, Stop 1.5 (Ages 7–9) · Explore Heroines of History and Faith · Expert, Stop 2.1 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.1 (Ages 10–13) · +3 more

cartilageEnglish
Tough, flexible tissue lighter than bone (the material in your ears and nose). A shark’s whole skeleton is made of it, strengthened in places with mineral.
Explore Animals · Expert, Stop 4.1 (Ages 14+) · Explore Animals · Ranger, Stop 4.1 (Ages 10–13) · Explore Animals, Stop 4.1 (Ages 7–9) · +3 more

casemateEnglish
An armored box or house built on a ship’s deck with guns firing through openings in its sides. The Virginia’s casemate had sloping iron walls.
Explore Great Battles · Expert, Stop 4.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 4.5 (Ages 10–13)

cash floatEnglish
The money, in small bills and coins, that a seller starts the day with in order to make change. It is not profit and is subtracted at the end.
Explore Crafts and Making · Expert, Stop 4.7 (Ages 14+)

casing stonesEnglish
The smooth, fine white limestone blocks that once covered the pyramids, making them shine; most were later stripped away for building in medieval Cairo.
Explore Travel and Faraway Places · Expert, Stop 4.6 (Ages 14+)

cast onEnglish
To make the first row of loops on a needle, the foundation every other row is built on. Common methods include the long-tail, knitted, cable and backward-loop cast-ons.
Explore Crafts and Making · Expert, Stop 2.3 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 2.3 (Ages 10–13) · Explore Crafts and Making, Stop 2.3 (Ages 7–9)

cast (replica)English
A copy made from a mold of a real specimen, often in plaster or resin. Most skeletons on display today are partly or wholly casts.
Explore Dinosaurs · Expert, Stop 5.10 (Ages 14+)

castaway storyEnglish
A tale of a person shipwrecked or stranded who must survive alone, in the tradition of Daniel Defoe’s Robinson Crusoe (1719).
Explore Horses and Ponies · Expert, Stop 4.7 (Ages 14+)

casteEnglish
A group within a colony with a particular body form or job: queen, worker, soldier or male.
Explore Animals · Expert, Stop 5.1 (Ages 14+) · Grade 6 Life Science: Animal Design and Behavior, Lesson 6.1 (grade 6)

catechismEnglish
A short book of Christian teaching by questions and answers. Luther’s Small Catechism (1529) included prayers for mealtimes.
Explore Hospitality and Home · Expert, Stop 2.5 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.5 (Ages 10–13)

catechumenEnglish
A person being taught the Christian faith in preparation for baptism. Perpetua and Felicity were catechumens when they were arrested.
Explore Heroines of History and Faith · Expert, Stop 2.1 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.1 (Ages 10–13) · Explore Heroines of History and Faith, Stop 2.1 (Ages 7–9)

caterpillarEnglish
The young, worm-like stage of a butterfly or moth that hatches from the egg and eats leaves.
Explore Animals, Stop 5.3 (Ages 7–9) · Grade 2 Gardening & Animals, Lesson 8.2 (grade 2) · Kindergarten Gardening & Animals, Lesson 8.2 (grade K) · +1 more

CathayEnglish
The medieval European name for northern China; southern China Polo called Manzi.
Explore Travel and Faraway Places · Expert, Stop 3.3 (Ages 14+)

Catholic (Nicene)English
The faith of the Nicene Creed, held by the bishops of Rome and Gaul: the Son is “of one substance with the Father.”
Explore Heroines of History and Faith · Expert, Stop 2.4 (Ages 14+)

cavalryEnglish
Soldiers who fight on horseback.
Explore Great Battles, Stop 1.4 (Ages 7–9) · Explore Great Battles, Stop 2.1 (Ages 7–9)

cavity nesterEnglish
A bird that nests inside a hole in a tree, cliff, bank or box, either digging it or using one already made.
Explore Animals · Expert, Stop 2.8 (Ages 14+) · Explore Animals · Ranger, Stop 2.8 (Ages 10–13) · Grade 6 Gardening & Animals, Lesson 2.4 (grade 6)

cecumEnglish
A large pouch at the start of the horse’s hindgut where helpful microbes break down tough plant fiber (say “SEE-kum”).
Explore Horses and Ponies · Ranger, Stop 2.5 (Ages 10–13)

celestial navigationEnglish
Finding latitude and longitude by measuring the sun, moon and stars with instruments such as the sextant and octant.
Explore Travel and Faraway Places · Expert, Stop 3.5 (Ages 14+)

centerpieceEnglish
A decoration in the middle of the table, usually of flowers, greenery, fruit or candles.
Explore Hospitality and Home · Expert, Stop 2.4 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.4 (Ages 10–13) · Explore Hospitality and Home, Stop 2.4 (Ages 7–9)

Central Asiatic ExpeditionsEnglish
The American Museum of Natural History’s expeditions to Mongolia and China in the 1920s, led by Roy Chapman Andrews.
Explore Dinosaurs · Expert, Stop 1.5 (Ages 14+) · Explore Dinosaurs · Expert, Stop 2.8 (Ages 14+)

central conflictEnglish
The main struggle that drives a plot. In Misty it is the struggle between wanting to own a wild horse and letting her be free.
Explore Horses and Ponies · Expert, Stop 4.4 (Ages 14+)

centralismEnglish
Government run from the national capital, with little power left to the states. Santa Anna’s turn to centralism in 1834–1835 helped set off rebellions in several Mexican states, including Texas.
Explore Great Battles · Expert, Stop 4.3 (Ages 14+)

centralistEnglish
A supporter of a strong national government in Mexico City with little power left to the states; the opposite of a federalist.
Explore Great Battles · Ranger, Stop 4.3 (Ages 10–13)

cephalopodEnglish
“Head-foot”: the group of mollusks (with snails and clams) that includes octopuses, squid, cuttlefish and the nautilus, whose arms grow from the head.
Explore Animals · Expert, Stop 4.2 (Ages 14+) · Explore Animals · Ranger, Stop 4.2 (Ages 10–13) · Grade 6 Life Science: Animal Design and Behavior, Lesson 4.1 (grade 6)

cephalothoraxEnglish
The front body section of a spider, a fused head and chest that carries the eyes, fangs, palps and all eight legs.
Explore Animals · Expert, Stop 5.4 (Ages 14+) · Explore Animals · Ranger, Stop 5.4 (Ages 10–13)

ceratopsianEnglish
A member of the horned and frilled plant-eating dinosaurs with a parrot-like beak, such as Triceratops and Protoceratops.
Explore Dinosaurs · Expert, Stop 1.2 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.2 (Ages 10–13)

cervical vertebraeEnglish
The bones of the neck. Mammals almost always have seven; some sauropods had up to nineteen.
Explore Dinosaurs · Expert, Stop 3.9 (Ages 14+) · Explore Dinosaurs · Expert, Stop 5.2 (Ages 14+) · Grade 7 Life Science: Cells and Microbes, Lesson 7.4 (grade 7)

cetaceanEnglish
The group of sea mammals that includes whales, dolphins and porpoises (from the Greek kētos, “sea monster” or “great fish”).
Explore Animals · Expert, Stop 1.3 (Ages 14+) · Explore Animals · Expert, Stop 4.5 (Ages 14+)

chameleonEnglish
A lizard that can change its color, move its eyes separately and catch insects with a long, sticky tongue (say “kuh-MEEL-yun”).
Explore Animals, Stop 3.5 (Ages 7–9)

character foilEnglish
A character whose different nature helps us see the main character more clearly, as fiery Ginger does for gentle Beauty.
Explore Horses and Ponies · Ranger, Stop 4.2 (Ages 10–13)

chargerEnglish
A horse trained to carry an officer in battle: calm under gunfire, quick to answer the rider, and strong enough for a long day.
Explore Horses and Ponies · Expert, Stop 3.3 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 3.3 (Ages 10–13) · Explore Horses and Ponies, Stop 3.3 (Ages 7–9) · +1 more

chariotEnglish
A light, two-wheeled vehicle pulled by horses, used in war and travel in Bible times by Egypt, Assyria and Israel.
Explore Animals · Expert, Stop 1.5 (Ages 14+) · Explore Great Battles, Stop 1.4 (Ages 7–9) · Explore Heroines of History and Faith · Ranger, Stop 1.3 (Ages 10–13) · +3 more

chariots of ironEnglish
Canaanite war chariots fitted with iron parts. Sisera had nine hundred (Judges 4:3), a terrifying force on open, dry ground.
Explore Heroines of History and Faith · Expert, Stop 1.3 (Ages 14+) · Explore Heroines of History and Faith, Stop 1.3 (Ages 7–9)

Charles MartelEnglish
The leader of the Franks. “Martel” means “the Hammer.”
Explore Great Battles, Stop 2.1 (Ages 7–9)

checked bagEnglish
A bag handed over at the airport to travel in the hold; usually limited to 50 pounds in economy and often charged a fee.
Explore Travel and Faraway Places · Expert, Stop 2.5 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.5 (Ages 10–13)

chemosynthesisEnglish
Making food from chemicals rather than sunlight. Bacteria at deep-sea hot springs do this, feeding whole communities of animals.
Explore Animals · Expert, Stop 4.7 (Ages 14+)

chesedEnglish
A Hebrew word for loyal, covenant love and kindness that goes beyond duty. The KJV often renders it “kindness” or “mercy”; it is the key idea of the Book of Ruth.
Explore Heroines of History and Faith · Expert, Stop 1.4 (Ages 14+)

chestnutEnglish
A red-brown coat with mane and tail the same color or lighter, with no black points. Western horsemen often say sorrel for lighter shades.
Explore Horses and Ponies · Expert, Stop 1.8 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.8 (Ages 10–13) · Explore Horses and Ponies, Stop 1.8 (Ages 7–9)

chevauchéeEnglish
A long armed march through enemy country to show strength, plunder and provoke battle; Henry’s march from Harfleur to Calais was meant partly as one.
Explore Great Battles · Expert, Stop 2.5 (Ages 14+)

Chicxulub craterEnglish
A buried impact crater about 180 km across under the Yucatán Peninsula of Mexico, identified as an impact structure in 1990–1991.
Explore Dinosaurs · Expert, Stop 4.7 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 4.7 (Ages 10–13)

China Inland MissionEnglish
A missionary society founded by Hudson Taylor in 1865 to bring the gospel to inland China. It turned Aylward down in 1930 after a trial period of study.
Explore Heroines of History and Faith · Expert, Stop 4.6 (Ages 14+) · Grade 7 Geography: Regions of the World, Lesson 6.4 (grade 7)

ChiropteraEnglish
The order of mammals made up of the bats. The name means “hand-wing,” because a bat’s wing is a hand with very long fingers.
Explore Animals · Expert, Stop 1.4 (Ages 14+) · Explore Animals · Ranger, Stop 1.4 (Ages 10–13)

chromatophoreEnglish
A tiny elastic sac of colored pigment in the skin, opened and closed by muscles controlled by nerves. Thousands of them let an octopus change color in a fraction of a second.
Explore Animals · Expert, Stop 4.2 (Ages 14+) · Explore Animals · Expert, Stop 6.2 (Ages 14+) · Explore Animals · Ranger, Stop 4.2 (Ages 10–13) · +2 more

chronicleEnglish
A history written year by year. The Mozarabic Chronicle of 754, written by a Christian in Spain, is our best early source for Tours.
Explore Great Battles · Ranger, Stop 2.1 (Ages 10–13) · Explore Dinosaurs · Ranger, Stop 4.6 (Ages 10–13)

chrysalisEnglish
The hard case of a butterfly pupa, inside which the caterpillar’s body is rebuilt into the adult.
Explore Animals · Expert, Stop 5.3 (Ages 14+) · Explore Animals · Ranger, Stop 5.3 (Ages 10–13) · Explore Animals, Stop 5.3 (Ages 7–9) · +1 more

Church of the Holy SepulchreEnglish
The church in Jerusalem built over the place of Christ’s crucifixion and burial, dedicated in 335.
Explore Heroines of History and Faith · Expert, Stop 2.2 (Ages 14+)

Church of the NativityEnglish
The church in Bethlehem over the place of Jesus’ birth.
Explore Heroines of History and Faith, Stop 2.2 (Ages 7–9) · Explore Travel and Faraway Places · Expert, Stop 4.1 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 4.1 (Ages 10–13)

churlishEnglish
The KJV’s word for Nabal: harsh, rude and mean-spirited. His name in Hebrew means “fool” (1 Samuel 25:25).
Explore Heroines of History and Faith · Expert, Stop 1.6 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 1.6 (Ages 10–13)

chytrid fungusEnglish
A microscopic fungus (Batrachochytrium dendrobatidis) that infects frog skin and has caused deaths of many frogs worldwide.
Explore Animals · Expert, Stop 3.7 (Ages 14+)

circumvallationEnglish
A second line of siege works built around the besiegers’ own camp, facing outward, to keep a relieving army out.
Explore Great Battles · Expert, Stop 1.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 1.7 (Ages 10–13)

citizen scienceEnglish
Science in which ordinary people, not only trained scientists, collect real observations that scientists use.
Explore Animals · Ranger, Stop 2.10 (Ages 10–13) · Grade 5 Gardening & Animals, Lesson 1.2 (grade 5) · Grade 8 Gardening & Animals, Lesson 2.3 (grade 8)

citizen scientistEnglish
An ordinary person who helps real scientists by watching and counting.
Explore Animals, Stop 2.10 (Ages 7–9) · Grade 4 Life Science: Classification, Lesson 4.3 (grade 4)

citizenshipEnglish
Membership in a nation, with the rights and duties that come with it; a passport is evidence of it.
Explore Travel and Faraway Places · Expert, Stop 2.6 (Ages 14+)

civil disobedienceEnglish
Refusing a ruler’s command because obeying it would mean disobeying God; in Exodus 1–2, refusing to take part in killing children.
Explore Heroines of History and Faith · Expert, Stop 1.2 (Ages 14+)

Civil WarEnglish
The war between the Union (the Northern states) and the Confederacy (the Southern states) in the United States, 1861–1865.
Explore Heroines of History and Faith · Ranger, Stop 4.2 (Ages 10–13) · Explore Heroines of History and Faith, Stop 4.2 (Ages 7–9) · Explore Horses and Ponies · Ranger, Stop 3.5 (Ages 10–13) · +1 more

civilityEnglish
Polite, considerate behavior toward others in public life. Erasmus’s book of 1530 made the word popular across Europe.
Explore Hospitality and Home · Expert, Stop 2.6 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.6 (Ages 10–13) · Explore Hospitality and Home · Ranger, Stop 3.5 (Ages 10–13)

claim shantyEnglish
A small, quickly built house on a homestead claim, often of rough boards or sod.
Explore Heroines of History and Faith · Ranger, Stop 3.8 (Ages 10–13)

claspEnglish
The fastener that opens and closes a bracelet or necklace, such as a lobster clasp or a toggle.
Explore Crafts and Making · Ranger, Stop 3.8 (Ages 10–13) · Explore Crafts and Making, Stop 3.8 (Ages 7–9)

clean and uncleanEnglish
Two groups of animals named in Genesis 7:2. Clean animals went on board by sevens; unclean animals by twos.
Explore Dinosaurs · Ranger, Stop 4.4 (Ages 10–13)

cleaning stationEnglish
A spot on a reef where small fish or shrimp remove parasites and dead skin from larger fish that come and wait to be cleaned.
Explore Animals · Expert, Stop 6.5 (Ages 14+) · Explore Animals · Ranger, Stop 6.5 (Ages 10–13)

clearEnglish
To take dishes away after eating.
Explore Hospitality and Home, Stop 2.7 (Ages 7–9)

clear from the rightEnglish
Used plates are removed from the diner’s right side, the side of the knife and glass, keeping the server’s arm out of his way.
Explore Hospitality and Home · Expert, Stop 2.7 (Ages 14+)

closed stud bookEnglish
A register that accepts only foals whose sire and dam are both already registered. No outside blood can enter.
Explore Horses and Ponies · Expert, Stop 1.3 (Ages 14+)

closed-mouth callEnglish
A low, booming sound made by puffing up the throat or chest with the mouth shut, as doves, emus and alligators do.
Explore Dinosaurs · Ranger, Stop 3.10 (Ages 10–13)

closed-mouth vocalizationEnglish
Making a sound by pushing air into a stretchy throat or esophagus with the mouth shut, like a dove’s coo or an ostrich’s boom.
Explore Dinosaurs · Expert, Stop 3.10 (Ages 14+)

closing errorEnglish
The gap between where a closed traverse ends on paper and where it began. It shows how accurate the survey was.
Explore Travel and Faraway Places · Expert, Stop 1.8 (Ages 14+)

cloverleaf patternEnglish
The barrel-racing course: a run around three barrels set in a triangle, in a pattern that looks like a three-leaf clover, timed to the hundredth of a second.
Explore Horses and Ponies · Expert, Stop 2.8 (Ages 14+)

ClovisEnglish
King of the Franks (ruled about 481–511).
Explore Heroines of History and Faith, Stop 2.4 (Ages 7–9)

clusterEnglish
A group of sights close together, visited on the same day to avoid crossing back and forth.
Explore Travel and Faraway Places · Expert, Stop 2.4 (Ages 14+) · Fabrics & Sewing I, Lesson 5.4 (grade 3–5) · Fabrics & Sewing II, Lesson 5.3 (grade 6–8)

ClydesdaleEnglish
A Scottish draft breed from the valley of the Clyde in Lanarkshire, usually bay with a white face, white legs and long feather, known for high, flashy action.
Explore Horses and Ponies · Expert, Stop 1.4 (Ages 14+)

coaching innEnglish
An inn on a main road where stagecoaches and mail coaches stopped to change horses and feed and lodge passengers; common in Britain from the 1600s to the 1840s.
Explore Hospitality and Home · Expert, Stop 4.5 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 4.5 (Ages 10–13) · Explore Hospitality and Home, Stop 4.5 (Ages 7–9)

coastEnglish
In the KJV, the border or territory of a land, not only the seashore: “all the coasts of Egypt” means all its territory.
Explore Animals · Expert, Stop 5.8 (Ages 14+) · Grade 1 Geography: Maps and Journeys, Lesson 3.4 (grade 1) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 2.1 (grade 2) · +3 more

cobEnglish
A short-legged, strong, sturdy riding or driving horse; the Welsh Cob is the largest Welsh section.
Explore Horses and Ponies · Ranger, Stop 1.6 (Ages 10–13)

code-breakerEnglish
A person who works out how to read the enemy’s secret messages.
Explore Great Battles, Stop 5.5 (Ages 7–9)

codexEnglish
A book of folded leaves fastened at one edge, as opposed to a scroll; Latin for a block of wood, from the wooden writing tablets that came first.
Explore Crafts and Making · Expert, Stop 3.7 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 3.7 (Ages 10–13) · Explore Crafts and Making, Stop 3.7 (Ages 7–9) · +1 more

Coercive ActsEnglish
Laws passed by Parliament in 1774 after the Boston Tea Party; they closed Boston’s port and changed Massachusetts’s charter government. Colonists called them the Intolerable Acts.
Explore Great Battles · Expert, Stop 3.4 (Ages 14+) · Explore Great Battles · Ranger, Stop 3.4 (Ages 10–13)

coffinEnglish
The medieval and Tudor English word for a pastry case; a pie was baked in its own “coffin,” which served as both pan and container.
Explore Hospitality and Home · Expert, Stop 1.7 (Ages 14+)

coffin boneEnglish
The last bone of the leg, shaped like a small hoof, held inside the hoof wall by hundreds of interlocking leaves of tissue called laminae.
Explore Horses and Ponies · Expert, Stop 2.4 (Ages 14+)

cog railwayEnglish
A mountain railway with a toothed rail in the middle that a gear on the train grips, so it can climb steep slopes.
Explore Travel and Faraway Places · Ranger, Stop 4.5 (Ages 10–13)

cold-bloodedEnglish
Getting its warmth from outside, from the sun or warm rocks, like lizards, snakes and turtles.
Explore Dinosaurs, Stop 3.6 (Ages 7–9) · Explore Horses and Ponies · Ranger, Stop 1.4 (Ages 10–13) · Grade 1 Life Science: Animal Homes and Habits, Lesson 4.2 (grade 1) · +2 more

ColeopteraEnglish
The scientific name of the beetle order, from Greek for “sheath wings.”
Explore Animals · Expert, Stop 5.5 (Ages 14+) · Explore Animals · Ranger, Stop 5.5 (Ages 10–13)

colicEnglish
Any pain in the abdomen; in horses usually from the gut. It ranges from mild gas to a twisted intestine needing surgery, and it is a leading cause of death in horses.
Explore Horses and Ponies · Expert, Stop 2.5 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.5 (Ages 10–13) · Grade 7 Gardening & Animals, Lesson 6.3 (grade 7)

collagen and gelatinEnglish
Collagen is the tough protein in bones, skin and connective tissue. Long, gentle heat in water breaks it down into gelatin, which gives good stock its body and makes it set like jelly when cold.
Explore Hospitality and Home · Expert, Stop 1.5 (Ages 14+)

colonial nestEnglish
One large nest structure shared by many birds, each family with its own chamber, as in the sociable weaver.
Explore Animals · Expert, Stop 6.4 (Ages 14+)

colonyEnglish
A family of social insects living together, usually one or a few egg-laying queens with their worker daughters and, at certain seasons, males.
Explore Animals · Expert, Stop 5.1 (Ages 14+) · Explore Animals · Ranger, Stop 2.4 (Ages 10–13) · Explore Animals · Ranger, Stop 2.8 (Ages 10–13) · +3 more

Colorado TerritoryEnglish
Colorado before statehood (1861–1876); Bird traveled there three years before it became a state.
Explore Travel and Faraway Places · Expert, Stop 3.6 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.6 (Ages 10–13)

ColosseumEnglish
A huge oval stadium of stone in Rome, opened in A.D. 80 (say “kol-oh-SEE-um”).
Explore Travel and Faraway Places, Stop 4.2 (Ages 7–9)

Columbian ExchangeEnglish
The transfer of plants, animals, people and diseases between the Eastern and Western Hemispheres after 1492.
Explore Travel and Faraway Places · Expert, Stop 3.4 (Ages 14+) · Grade 5 Geography: Explorers, Navigators and Missionaries, Lesson 8.3 (grade 5)

combEnglish
Sheets of six-sided wax cells built by workers to raise young and store honey and pollen.
Explore Animals · Expert, Stop 5.2 (Ages 14+) · Explore Animals · Ranger, Stop 5.2 (Ages 10–13) · Grade 3 Gardening & Animals, Lesson 6.1 (grade 3)

Combahee River Raid (June 1863)English
A Union raid in South Carolina, guided by Tubman’s scouting, that freed about 750 enslaved people from rice plantations.
Explore Heroines of History and Faith · Expert, Stop 4.3 (Ages 14+)

combat air patrol (CAP)English
Fighters kept circling over a fleet to shoot down attacking planes.
Explore Great Battles · Expert, Stop 5.5 (Ages 14+)

Combined FleetEnglish
The allied French and Spanish fleet under Vice Admiral Pierre de Villeneuve, with Admiral Federico Gravina commanding the Spanish.
Explore Great Battles · Expert, Stop 3.8 (Ages 14+)

commensalismEnglish
A relationship in which one partner benefits and the other is neither helped nor harmed, such as egrets following cattle to catch insects.
Explore Animals · Expert, Stop 6.5 (Ages 14+) · Explore Animals · Ranger, Stop 6.5 (Ages 10–13)

commentariiEnglish
Caesar’s own written accounts of his campaigns, “commentaries” or field reports, written in the third person; the Gallic War is our main source for Alesia.
Explore Great Battles · Expert, Stop 1.7 (Ages 14+) · Grade 8 Latin, Lesson 4.2 (grade 8)

commercial collectorEnglish
A fossil hunter who digs and prepares fossils for sale, rather than for a university or museum.
Explore Dinosaurs · Expert, Stop 2.9 (Ages 14+)

communal nestEnglish
A nest in which several females lay their eggs, as ostriches do.
Explore Animals · Expert, Stop 2.5 (Ages 14+)

community (citizen) scienceEnglish
Scientific research in which ordinary volunteers collect data, such as bird counts, that scientists then combine and analyze.
Explore Animals · Expert, Stop 2.10 (Ages 14+)

Commutation ActEnglish
The British law of 1784 that cut the tax on tea from about 119 percent to 12.5 percent, ending large-scale tea smuggling and making tea affordable to ordinary families.
Explore Hospitality and Home · Expert, Stop 2.8 (Ages 14+)

Companion cavalryEnglish
The elite heavy cavalry of Macedon, about 2,000 strong at Gaugamela, led personally by Alexander and often formed in a wedge.
Explore Great Battles · Expert, Stop 1.4 (Ages 14+) · Explore Horses and Ponies · Expert, Stop 3.1 (Ages 14+) · Tactics & Strategy, Lesson 3.3 (grade 8–12)

CompanionsEnglish
Alexander’s heavy cavalry, made up of Macedonian nobles who rode and fought beside the king.
Explore Great Battles · Ranger, Stop 1.4 (Ages 10–13)

comparative anatomyEnglish
The study of how the bodies of different animals compare, used to identify an unknown bone by matching it with known ones.
Explore Dinosaurs · Expert, Stop 2.2 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 2.3 (Ages 10–13) · Grade 5 Life Science: The Human Body, Lesson 9.3 (grade 5) · +1 more

complete checklistEnglish
A checklist that reports every species identified, so a species left off can be read as “not detected.”
Explore Animals · Expert, Stop 2.10 (Ages 14+)

complete metamorphosisEnglish
A life cycle with four very different stages: egg, larva (caterpillar), pupa (chrysalis) and adult.
Explore Animals · Expert, Stop 5.3 (Ages 14+) · Grade 4 Gardening & Animals, Lesson 8.3 (grade 4) · Grade 5 Gardening & Animals, Lesson 8.2 (grade 5) · +3 more

complete (of a fossil)English
How much of an animal’s skeleton was found. SUE is about 90 percent complete by bulk, which is very rare.
Explore Dinosaurs · Ranger, Stop 2.9 (Ages 10–13)

compound eyeEnglish
An eye made of thousands of tiny units (ommatidia), each with its own lens; a large dragonfly’s eye may have about 30,000.
Explore Animals · Expert, Stop 5.7 (Ages 14+) · Explore Animals · Ranger, Stop 5.7 (Ages 10–13) · Explore Animals, Stop 5.7 (Ages 7–9)

concentrateEnglish
Grain or a commercial feed (oats, corn, pellets) that packs more energy into a small volume; used only when forage alone is not enough for the work.
Explore Horses and Ponies · Expert, Stop 2.5 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.5 (Ages 10–13)

concentration campEnglish
A prison camp where the Nazis held huge numbers of people under cruel conditions, and where many died.
Explore Heroines of History and Faith · Ranger, Stop 4.7 (Ages 10–13)

concentric castleEnglish
A castle with one ring of walls inside another, so that attackers who break the outer wall face a higher inner wall; Henry III and Edward I made the Tower one in the 1200s.
Explore Travel and Faraway Places · Expert, Stop 4.3 (Ages 14+)

ConfederacyEnglish
The Confederate States of America, the government formed by the seceded states (1861–1865).
Explore Great Battles · Ranger, Stop 4.4 (Ages 10–13) · Explore Great Battles, Stop 4.4 (Ages 7–9)

ConfessionsEnglish
Augustine’s book in thirteen parts (written about 397–400), told as a long prayer to God about his life and conversion. It is our main source for Monica.
Explore Heroines of History and Faith · Expert, Stop 2.3 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.3 (Ages 10–13) · Explore Heroines of History and Faith, Stop 2.3 (Ages 7–9)

confessorEnglish
A priest who hears a person’s confession and gives spiritual guidance.
Explore Heroines of History and Faith · Expert, Stop 2.6 (Ages 14+)

conformal projectionEnglish
A projection that keeps angles and small shapes true but changes sizes. The Mercator projection is conformal.
Explore Travel and Faraway Places · Expert, Stop 1.1 (Ages 14+) · Geopolitics: The Great Ideas, Lesson 1.4 (grade 9–12)

conformationEnglish
The build of a horse: the shape, length and angle of its bones and how the parts fit together. Good conformation suits a horse for its work and helps keep it sound.
Explore Horses and Ponies · Expert, Stop 2.1 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.1 (Ages 10–13) · Explore Horses and Ponies · Ranger, Stop 2.1 (Ages 10–13) · +1 more

conical teethEnglish
Straight, cone-shaped teeth without sharp cutting edges, good for gripping slippery prey.
Explore Dinosaurs · Ranger, Stop 1.7 (Ages 10–13)

conscientious objectorEnglish
A person who refuses to fight in war for reasons of conscience, often religious ones.
Explore Great Battles · Expert, Stop 5.2 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.2 (Ages 10–13)

consecrateEnglish
To set apart as holy. Lincoln said the soldiers who fought at Gettysburg had consecrated the ground.
Explore Great Battles · Expert, Stop 4.7 (Ages 14+)

conservation herdEnglish
A herd kept mainly to preserve the bison as a wild animal (in parks, refuges or tribal lands), as opposed to a commercial herd raised for meat.
Explore Animals · Expert, Stop 1.10 (Ages 14+)

constableEnglish
The chief commander of the French royal army. In 1415 it was Charles d’Albret.
Explore Great Battles · Ranger, Stop 2.5 (Ages 10–13)

ConstantineEnglish
The first Roman emperor to become a Christian (ruled 306–337).
Explore Heroines of History and Faith, Stop 2.2 (Ages 7–9)

ConstantinopleEnglish
A great city on the water between Europe and Asia, the capital of the Eastern Roman (Byzantine) Empire. Today it is Istanbul, in Turkey.
Explore Great Battles, Stop 2.7 (Ages 7–9)

constrainedEnglish
An old word: urged strongly.
Explore Hospitality and Home, Stop 4.7 (Ages 7–9)

constrictorEnglish
A snake that kills its prey by wrapping around it and squeezing, such as a python or boa.
Explore Animals · Ranger, Stop 3.3 (Ages 10–13)

continentEnglish
One of the seven great pieces of land on the earth, such as Africa or North America.
Explore Travel and Faraway Places, Stop 1.1 (Ages 7–9) · Grade 1 Geography: Maps and Journeys, Lesson 9.4 (grade 1) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 4.1 (grade 3) · +3 more

Continental ArmyEnglish
The army of the united colonies, created by the Continental Congress in 1775 and commanded by George Washington.
Explore Great Battles · Ranger, Stop 3.5 (Ages 10–13) · Explore Great Battles, Stop 3.5 (Ages 7–9)

Continental CongressEnglish
The assembly of delegates from the colonies that met at Philadelphia from 1774, directed the war and declared independence on 4 July 1776. John Adams was a leading member.
Explore Heroines of History and Faith · Expert, Stop 3.6 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 3.6 (Ages 10–13) · Explore Heroines of History and Faith, Stop 3.6 (Ages 7–9)

Continental DivideEnglish
The line of high ground in the Rockies that separates rivers flowing to the Atlantic and Gulf from rivers flowing to the Pacific.
Explore Travel and Faraway Places · Expert, Stop 3.5 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.5 (Ages 10–13) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.3 (grade 2) · +3 more

Continental styleEnglish
Keep the fork in the left hand, tines down, and the knife in the right throughout, bringing food to the mouth with the left hand. Usual in Britain and Europe.
Explore Hospitality and Home · Expert, Stop 2.6 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.6 (Ages 10–13)

contravallationEnglish
A line of siege works built around a besieged place, facing inward, to keep the defenders in.
Explore Great Battles · Expert, Stop 1.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 1.7 (Ages 10–13)

conventEnglish
A house where nuns live together under religious rules, apart from the world.
Explore Heroines of History and Faith · Ranger, Stop 3.1 (Ages 10–13) · Explore Heroines of History and Faith, Stop 3.1 (Ages 7–9)

convergenceEnglish
Similar shapes in animals that are not closely related, such as the streamlined bodies of sharks (fish), ichthyosaurs (reptiles) and dolphins (mammals).
Explore Dinosaurs · Expert, Stop 5.1 (Ages 14+) · Explore Dinosaurs · Expert, Stop 5.7 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 5.1 (Ages 10–13)

convergence of evidenceEnglish
Several independent lines of evidence pointing to the same conclusion, which makes the conclusion stronger.
Explore Dinosaurs · Expert, Stop 3.1 (Ages 14+)

conversationEnglish
Talking and listening back and forth.
Explore Hospitality and Home, Stop 2.6 (Ages 7–9)

Coordinated Universal Time (UTC)English
The world’s reference time, kept by atomic clocks and matched to the old Greenwich Mean Time. Zones are written as UTC−5, UTC+9 and so on.
Explore Travel and Faraway Places · Expert, Stop 1.5 (Ages 14+)

coproliteEnglish
Fossilized dung. It can show what an animal actually ate.
Explore Dinosaurs · Expert, Stop 1.1 (Ages 14+) · Explore Dinosaurs · Expert, Stop 2.1 (Ages 14+) · Explore Dinosaurs · Expert, Stop 3.1 (Ages 14+) · +3 more

coralEnglish
A tiny sea animal that builds a hard cup around itself; many corals living together make a reef.
Explore Animals, Stop 4.3 (Ages 7–9) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 5.4 (grade 2)

coral bleachingEnglish
When stressed corals, often by unusually warm water, expel their algae and turn white. Corals can recover if the stress ends soon; if it lasts, they may starve and die.
Explore Animals · Expert, Stop 4.3 (Ages 14+)

correspondenceEnglish
Letters written back and forth.
Explore Heroines of History and Faith, Stop 3.6 (Ages 7–9)

cost per pieceEnglish
Batch cost ÷ number of pieces the batch makes. Also called cost per serving or cost per unit.
Explore Hospitality and Home · Expert, Stop 4.3 (Ages 14+)

cost per travelerEnglish
The total cost of a mode divided by the number of people sharing it. A car costs about the same for one person or five; tickets are paid per seat.
Explore Travel and Faraway Places · Expert, Stop 2.2 (Ages 14+)

costsEnglish
All the money you spent to make your products.
Explore Crafts and Making, Stop 4.8 (Ages 7–9)

cottage food lawEnglish
A state or local rule that says which home-baked foods may be sold to the public and how they must be labeled. Rules differ from place to place.
Explore Hospitality and Home · Expert, Stop 4.2 (Ages 14+)

couchingEnglish
Laying a thread on the surface of fabric and tacking it down with small stitches; used to fill the shapes in the Bayeux Tapestry.
Explore Crafts and Making · Ranger, Stop 2.5 (Ages 10–13)

council of warEnglish
A meeting in which a commander asks his officers for advice before deciding what to do.
Explore Great Battles · Ranger, Stop 4.3 (Ages 10–13)

countEnglish
The number of squares (stitches) per inch of fabric; 14-count Aida has 14 squares in each inch.
Explore Crafts and Making · Ranger, Stop 2.7 (Ages 10–13) · Explore Crafts and Making, Stop 2.7 (Ages 7–9)

countdownEnglish
A timeline that lists every job, working backward from the hour the guests arrive.
Explore Hospitality and Home · Ranger, Stop 3.8 (Ages 10–13)

counted threadEnglish
Embroidery worked by counting the threads or holes of the fabric instead of following lines drawn on it.
Explore Crafts and Making · Ranger, Stop 2.7 (Ages 10–13)

counted thread workEnglish
Needlework in which every stitch is placed by counting the threads of the fabric rather than following a line drawn on it.
Explore Crafts and Making · Expert, Stop 2.7 (Ages 14+)

counterattackEnglish
An attack made by an army that has been defending or falling back.
Explore Great Battles · Ranger, Stop 5.1 (Ages 10–13)

countercurrent heat exchangeEnglish
An arrangement of blood vessels in which warm blood flowing out to the feet or flippers passes close to cold blood flowing back, so heat is handed back to the body instead of lost.
Explore Animals · Expert, Stop 2.4 (Ages 14+)

countershadingEnglish
Being darker on top and lighter underneath, which cancels the shadow sunlight casts on the lower body and makes a solid animal look flat (Thayer’s law).
Explore Animals · Expert, Stop 6.2 (Ages 14+) · Explore Animals · Ranger, Stop 2.4 (Ages 10–13) · Explore Animals · Ranger, Stop 6.2 (Ages 10–13) · +1 more

courtesyEnglish
Polite, considerate behavior that shows respect for others; from the manners expected at a king’s court.
Explore Travel and Faraway Places · Expert, Stop 2.7 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.7 (Ages 10–13) · Explore Travel and Faraway Places, Stop 2.7 (Ages 7–9)

courtesy bookEnglish
A book of rules for behavior in company, especially at table. Courtesy books were written for boys in noble service from the Middle Ages onward.
Explore Hospitality and Home · Expert, Stop 2.6 (Ages 14+)

courtesy titleEnglish
A respectful title used with a last name: Mr., Mrs., Miss, Dr., Pastor, Captain and so on.
Explore Hospitality and Home · Ranger, Stop 3.6 (Ages 10–13)

covertureEnglish
The English common-law rule that a married woman’s legal identity was “covered” by her husband’s. Her property and earnings were legally his, and she could not usually make contracts or sue in her own name.
Explore Heroines of History and Faith · Expert, Stop 3.6 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 3.6 (Ages 10–13)

cow senseEnglish
A horse’s instinct and trained skill for reading cattle: anticipating which way a cow will turn and moving to block it, sometimes before the rider asks.
Explore Horses and Ponies · Expert, Stop 1.5 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.5 (Ages 10–13) · Explore Horses and Ponies, Stop 1.5 (Ages 7–9)

craftsmanEnglish
A person skilled at making things by hand, such as metalwork, carving, weaving or embroidery.
Explore Crafts and Making · Ranger, Stop 4.1 (Ages 10–13) · Explore Crafts and Making, Stop 4.1 (Ages 7–9)

creaseEnglish
A sharp line made by folding paper and pressing it flat.
Explore Crafts and Making, Stop 3.2 (Ages 7–9) · Explore Hospitality and Home, Stop 2.3 (Ages 7–9)

crease patternEnglish
The map of lines left on a square when a finished model is unfolded; designers now often plan models from the crease pattern first.
Explore Crafts and Making · Expert, Stop 3.2 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 3.2 (Ages 10–13)

creation weekEnglish
The six days in which God made the heavens, the earth and all that is in them, and the seventh day on which He rested (Genesis 1–2; Exodus 20:11).
Explore Dinosaurs · Ranger, Stop 4.1 (Ages 10–13)

crècheEnglish
A group of penguin chicks gathered together for warmth and safety while both parents are away fishing.
Explore Animals · Expert, Stop 2.4 (Ages 14+)

crewelworkEnglish
Embroidery in fine twisted wool, especially popular in England and colonial America in the 1600s and 1700s for bed hangings and curtains.
Explore Crafts and Making · Expert, Stop 2.5 (Ages 14+)

Crimean WarEnglish
A war of 1853–1856 in which Britain, France, the Ottoman Empire and Sardinia fought Russia, mostly on the Crimean peninsula in the Black Sea.
Explore Heroines of History and Faith · Ranger, Stop 4.1 (Ages 10–13) · Explore Heroines of History and Faith, Stop 4.1 (Ages 7–9)

Crimean War (1853–1856)English
A war in which Britain, France, the Ottoman Empire and Sardinia fought Russia, mainly on the Crimean peninsula in the Black Sea.
Explore Heroines of History and Faith · Expert, Stop 4.1 (Ages 14+)

crimpEnglish
The natural waves along a wool fiber. Crimp traps air for warmth and helps fibers grip one another when they are spun.
Explore Crafts and Making · Expert, Stop 2.1 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 1.7 (Ages 10–13) · Fabrics & Sewing I, Lesson 1.2 (grade 3–5) · +2 more

crimp beadEnglish
A soft metal tube squeezed flat with pliers to hold beading wire in a loop at a clasp.
Explore Crafts and Making · Ranger, Stop 3.8 (Ages 10–13)

crocodileEnglish
A large reptile with a long snout, strong jaws and a long tail that lives in and near warm rivers, swamps and coasts.
Explore Animals, Stop 3.1 (Ages 7–9)

crocodilianEnglish
Any member of the order Crocodylia: true crocodiles, alligators and caimans, and gharials. About 27 living species are usually recognized.
Explore Animals · Expert, Stop 3.1 (Ages 14+) · Explore Animals · Ranger, Stop 3.1 (Ages 10–13) · Grade 2 Life Science: Animal Families, Lesson 3.3 (grade 2)

cross stitchEnglish
A counted stitch made of two diagonal stitches that cross in an X over a square of fabric threads; the top stitch always slants the same way.
Explore Crafts and Making · Expert, Stop 2.7 (Ages 14+)

crossroadsEnglish
A place where roads meet. Armies need roads to move trucks, tanks and supplies.
Explore Great Battles, Stop 5.8 (Ages 7–9)

cross-stitchEnglish
An X-shaped stitch made of two slanted stitches crossing in the middle, worked over a square of fabric threads.
Explore Crafts and Making · Ranger, Stop 2.7 (Ages 10–13) · Explore Crafts and Making, Stop 2.7 (Ages 7–9)

Crown JewelsEnglish
The crowns, scepters and other regalia used to crown English and British kings and queens, kept in the Tower’s Jewel House.
Explore Travel and Faraway Places · Ranger, Stop 4.3 (Ages 10–13) · Explore Travel and Faraway Places, Stop 4.3 (Ages 7–9)

crumbingEnglish
Brushing crumbs from the tablecloth onto a small tray or plate before dessert, using a folded napkin or a crumb brush.
Explore Hospitality and Home · Expert, Stop 2.7 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.7 (Ages 10–13)

crusadeEnglish
A war in the Middle Ages to win back the Holy Land.
Explore Heroines of History and Faith, Stop 2.7 (Ages 7–9)

Crusader statesEnglish
The Christian kingdoms and counties set up in Syria and the Holy Land after the First Crusade (1099), led by the Kingdom of Jerusalem.
Explore Great Battles · Ranger, Stop 2.3 (Ages 10–13)

CrusadersEnglish
Christian soldiers from Europe who went to the Holy Land. Their kingdom there was called the Kingdom of Jerusalem.
Explore Great Battles, Stop 2.3 (Ages 7–9)

cryoprotectantEnglish
A substance, such as glucose in a wood frog, that protects cells from damage by freezing.
Explore Animals · Expert, Stop 6.3 (Ages 14+)

cryptanalysisEnglish
Breaking codes and ciphers without being given the key. The Japanese naval code the Americans attacked was called JN-25.
Explore Great Battles · Expert, Stop 5.5 (Ages 14+)

cryptanalystEnglish
A code-breaker: a person who works out the meaning of secret messages without the key.
Explore Great Battles · Ranger, Stop 5.5 (Ages 10–13)

Crystal PalaceEnglish
A huge glass and iron hall built for the Great Exhibition of 1851 in Hyde Park, then rebuilt larger at Sydenham in south London, reopening in 1854.
Explore Dinosaurs · Expert, Stop 2.5 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 2.5 (Ages 10–13)

CT scanEnglish
A series of X-ray images that a computer stacks into a 3-D picture of the inside of an object, such as a fossil skull.
Explore Dinosaurs · Expert, Stop 1.8 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.8 (Ages 10–13) · Explore Dinosaurs, Stop 1.8 (Ages 7–9)

cubEnglish
A baby bear.
Explore Animals, Stop 1.7 (Ages 7–9) · Grade 1 Life Science: Animal Homes and Habits, Lesson 1.4 (grade 1)

cumberedEnglish
In the KJV, weighed down or distracted. The Greek word suggests being pulled away in many directions.
Explore Hospitality and Home · Expert, Stop 3.3 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 3.3 (Ages 10–13) · Explore Hospitality and Home, Stop 3.3 (Ages 7–9)

cunning workEnglish
In the English of 1611, “cunning” means skillful and knowing, not sly. “Cunning work” is expert, finely designed workmanship.
Explore Crafts and Making · Expert, Stop 4.1 (Ages 14+)

Curaray RiverEnglish
A river in the Ecuadorian rainforest. The missionaries landed on a sandbar there they called “Palm Beach.”
Explore Heroines of History and Faith · Expert, Stop 4.8 (Ages 14+)

curatorEnglish
A person who takes care of a museum’s collection and plans its displays.
Explore Dinosaurs, Stop 5.10 (Ages 7–9) · Sports & Games of the World, Lesson 2.1 (grade 4–7)

curb bitEnglish
A bit with shanks and a curb chain or strap under the chin; it works as a lever, multiplying the rein’s pull and adding pressure on the chin groove and poll.
Explore Horses and Ponies · Expert, Stop 2.2 (Ages 14+)

currencyEnglish
The kind of money a country uses, such as dollars, euros or yen.
Explore Travel and Faraway Places, Stop 2.6 (Ages 7–9)

curry combEnglish
A rubber or plastic comb with short teeth or ridges, rubbed in small circles over the fleshy parts of the body to loosen dirt, dead hair and scurf.
Explore Horses and Ponies · Expert, Stop 2.3 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.3 (Ages 10–13) · Explore Horses and Ponies, Stop 2.3 (Ages 7–9) · +2 more

cursorialEnglish
Built for running: long lower legs, long feet and a light build, as in ostriches and horses.
Explore Dinosaurs · Expert, Stop 3.5 (Ages 14+)

cushionEnglish
Extra money set aside for surprises, often about one tenth of the budget.
Explore Travel and Faraway Places · Ranger, Stop 2.3 (Ages 10–13) · Threads & Weaving, Lesson 7.4 (grade 9–12)

customsEnglish
The government service at a border that checks goods coming in, collects any duties (taxes on imports) and stops forbidden items.
Explore Travel and Faraway Places · Expert, Stop 2.6 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.6 (Ages 10–13) · Explore Travel and Faraway Places, Stop 2.6 (Ages 7–9)

cut inEnglish
To work cold fat into flour with a pastry blender, two knives or quick fingertips until the pieces are the size of peas.
Explore Hospitality and Home · Ranger, Stop 1.7 (Ages 10–13) · Explore Hospitality and Home, Stop 1.7 (Ages 7–9)

cutaneous respirationEnglish
Breathing through the skin. Oxygen passes through a frog’s thin, moist skin into tiny blood vessels just beneath it.
Explore Animals · Expert, Stop 3.7 (Ages 14+) · Grade 7 Life Science: Cells and Microbes, Lesson 8.2 (grade 7)

cuttingEnglish
Separating one animal from a herd and keeping it from returning. Today it is also a competition in which the rider loosens the reins and lets the horse work the cow alone.
Explore Horses and Ponies · Expert, Stop 1.5 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.5 (Ages 10–13) · Body Mechanics of Sport, Lesson 3.4 (grade 8–12)

cyanotypeEnglish
A photographic print in white on deep blue, made by laying an object on paper coated with iron salts and setting it in sunlight; invented by Sir John Herschel in 1842.
Explore Crafts and Making · Expert, Stop 3.6 (Ages 14+)

CyprusEnglish
A Venetian island in the eastern Mediterranean invaded by the Ottomans in 1570. Its last fortress, Famagusta, surrendered in August 1571, before Lepanto was fought.
Explore Great Battles · Expert, Stop 2.8 (Ages 14+)

Dakota TerritoryEnglish
The federal territory that in 1889 became North and South Dakota. The Ingalls family settled at De Smet in its eastern part in 1879.
Explore Heroines of History and Faith · Expert, Stop 3.8 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 3.8 (Ages 10–13)

damaskEnglish
A reversible woven fabric, often white linen, whose pattern appears by the way the threads catch the light. Fine table linen was woven in damask.
Explore Hospitality and Home · Expert, Stop 2.3 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.3 (Ages 10–13)

dandy brushEnglish
A stiff-bristled brush, flicked in short strokes with the lie of the hair, that sweeps away what the curry comb has loosened.
Explore Horses and Ponies · Expert, Stop 2.3 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.3 (Ages 10–13) · Explore Horses and Ponies, Stop 2.3 (Ages 7–9)

datingEnglish
Working out how old something is.
Explore Dinosaurs, Stop 4.9 (Ages 7–9)

DauphinEnglish
The title of the heir to the French throne. Charles, son of Charles VI, was called the Dauphin until his coronation at Reims in July 1429 made him Charles VII.
Explore Great Battles · Expert, Stop 2.6 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.6 (Ages 10–13) · Explore Great Battles, Stop 2.6 (Ages 7–9) · +3 more

daylight saving timeEnglish
Setting clocks one hour ahead in the warm months so that more daylight falls in the evening.
Explore Travel and Faraway Places · Expert, Stop 1.5 (Ages 14+)

D-DayEnglish
The day a big attack begins. The most famous D-Day is June 6, 1944, when the Allies landed in France.
Explore Great Battles, Stop 5.7 (Ages 7–9)

Deccan TrapsEnglish
A huge series of lava flows in western India, more than a kilometer thick in places, which some scientists link to the dinosaurs’ extinction.
Explore Dinosaurs · Expert, Stop 4.7 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 4.7 (Ages 10–13)

deceptionEnglish
Misleading the enemy about where and when you will attack. At El Alamein the plan was called Operation Bertram.
Explore Great Battles · Expert, Stop 5.6 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.6 (Ages 10–13) · Explore Great Battles, Stop 5.6 (Ages 7–9) · +3 more

Declaration of ArbroathEnglish
A letter of 1320 from the barons of Scotland to Pope John XXII, defending Scotland’s independence and Robert I’s kingship.
Explore Great Battles · Expert, Stop 2.4 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.4 (Ages 10–13)

declaration of causesEnglish
A formal statement by a seceding state explaining why it left the Union. South Carolina, Mississippi, Georgia and Texas issued them.
Explore Great Battles · Expert, Stop 4.4 (Ages 14+)

dedicateEnglish
To set apart a place for a solemn purpose, such as a cemetery for those who died.
Explore Great Battles · Ranger, Stop 4.7 (Ages 10–13)

deep seaEnglish
The deepest part of the ocean, where sunlight never reaches.
Explore Animals, Stop 4.7 (Ages 7–9)

degree, minute, secondEnglish
Units for dividing a circle: 360 degrees in a circle, 60 minutes in a degree, 60 seconds in a minute. Written 38° 53′ 23″.
Explore Travel and Faraway Places · Expert, Stop 1.3 (Ages 14+)

delayed implantationEnglish
A pause in which a fertilized egg waits for months before it attaches in the womb and begins to grow. In bears it lets cubs be born in the den in midwinter.
Explore Animals · Expert, Stop 1.7 (Ages 14+)

demand forecastEnglish
A reasoned estimate of how much customers will buy, built from numbers such as attendance and past sales.
Explore Hospitality and Home · Expert, Stop 4.2 (Ages 14+)

demineralizeEnglish
To dissolve away the hard calcium-phosphate mineral of bone with a mild acid or chelating agent, leaving any organic material behind.
Explore Dinosaurs · Expert, Stop 2.10 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 2.10 (Ages 10–13) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 5.2 (grade 8)

denEnglish
A sheltered resting place, such as a cave, hollow log or dug-out hole, where a bear spends the winter.
Explore Animals · Ranger, Stop 1.7 (Ages 10–13) · Explore Animals, Stop 1.7 (Ages 7–9) · Explore Animals, Stop 6.3 (Ages 7–9) · +3 more

denningEnglish
Spending the winter in a den in a deep, energy-saving sleep. Many scientists call it hibernation; others reserve that word for animals whose body temperature drops much further.
Explore Animals · Expert, Stop 1.7 (Ages 14+)

dental batteryEnglish
Hundreds of teeth packed in columns, with new teeth growing up underneath to replace worn ones, forming one long grinding and slicing surface.
Explore Dinosaurs · Expert, Stop 1.2 (Ages 14+) · Explore Dinosaurs · Expert, Stop 3.1 (Ages 14+) · Explore Dinosaurs · Expert, Stop 4.10 (Ages 14+) · +3 more

dermal denticlesEnglish
“Skin teeth”: tiny, tooth-like scales covering a shark’s skin. They point backward, make the skin feel like sandpaper and reduce drag in the water.
Explore Animals · Expert, Stop 4.1 (Ages 14+) · Explore Animals · Ranger, Stop 4.1 (Ages 10–13)

Desert FoxEnglish
The nickname of the German general Erwin Rommel, because he was quick and clever.
Explore Great Battles, Stop 5.6 (Ages 7–9)

designEnglish
A plan for how something is made so that it works well.
Explore Animals, Stop 6.9 (Ages 7–9) · Explore Dinosaurs · Ranger, Stop 4.10 (Ages 10–13) · Explore Dinosaurs, Stop 4.10 (Ages 7–9) · +1 more

design argumentEnglish
The argument that features of the natural world show purpose and point to a wise Designer (Romans 1:20).
Explore Dinosaurs · Expert, Stop 4.10 (Ages 14+) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 4.1 (grade 8)

dessert spoonEnglish
A spoon placed above the plate for dessert.
Explore Hospitality and Home, Stop 2.2 (Ages 7–9)

destinationEnglish
The place a journey is meant to reach. A trip may have one destination or several stops along a route.
Explore Travel and Faraway Places · Expert, Stop 2.1 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.1 (Ages 10–13) · Explore Travel and Faraway Places, Stop 2.1 (Ages 7–9)

diagnosisEnglish
In naming, the list of features that sets a group apart from all others.
Explore Dinosaurs · Expert, Stop 2.4 (Ages 14+) · Grade 4 Gardening & Animals, Lesson 8.4 (grade 4) · Grade 7 Gardening & Animals, Lesson 8.1 (grade 7) · +1 more

diagonal pairEnglish
A front leg and the opposite hind leg (left fore with right hind), which move together at the trot.
Explore Horses and Ponies · Expert, Stop 2.6 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.6 (Ages 10–13)

Diary of MererEnglish
Papyrus logbooks found in 2013 at Wadi al-Jarf on the Red Sea, kept by an official named Merer whose team ferried limestone to Giza for Khufu’s pyramid; they are among the oldest written papyri ever found.
Explore Travel and Faraway Places · Expert, Stop 4.6 (Ages 14+)

diasporaEnglish
The scattering of the Jewish people outside the land of Israel after the Babylonian exile. Many stayed in Persia even after Cyrus let them return in 538 B.C.
Explore Heroines of History and Faith · Expert, Stop 1.7 (Ages 14+) · Human Geography, Lesson 4.3 (grade 9–12)

dichotomous keyEnglish
A tool for identifying a living thing by a series of two-choice questions.
Explore Animals · Expert, Stop 6.10 (Ages 14+) · Grade 5 Gardening & Animals, Lesson 2.1 (grade 5) · Grade 4 Life Science: Classification, Lesson 1.4 (grade 4) · +3 more

Dickin MedalEnglish
A British medal for animal bravery in war, awarded by the charity PDSA; Reckless received it after her death, in 2016.
Explore Horses and Ponies · Expert, Stop 3.6 (Ages 14+)

diluvialEnglish
Having to do with the Flood (Latin diluvium). Early geologists called certain gravels and cave deposits “diluvium.”
Explore Dinosaurs · Expert, Stop 2.2 (Ages 14+)

diphtheriaEnglish
A dangerous bacterial disease that forms a thick coating in the throat and can close the airway; it struck children hardest before vaccines were common.
Explore Animals · Expert, Stop 6.8 (Ages 14+) · Explore Animals · Ranger, Stop 6.8 (Ages 10–13)

dire wolfEnglish
A large extinct wolf, heavier than a gray wolf, with a big head and strong teeth. It is the most common large mammal at La Brea.
Explore Dinosaurs · Ranger, Stop 5.9 (Ages 10–13) · Explore Dinosaurs, Stop 5.9 (Ages 7–9)

direct costEnglish
A cost tied to each item you make, such as ingredients and the bag it is sold in.
Explore Hospitality and Home · Expert, Stop 4.3 (Ages 14+)

disaster reliefEnglish
Help given after a flood, fire, storm or other disaster: food, shelter, clothing and medical care.
Explore Heroines of History and Faith · Ranger, Stop 4.2 (Ages 10–13)

discipleEnglish
A learner who follows a teacher. To “sit at the feet” of a teacher was the place of a disciple.
Explore Hospitality and Home · Ranger, Stop 3.3 (Ages 10–13)

dished faceEnglish
A face with a concave, inward curve between the eyes and the muzzle, a hallmark of the Arabian.
Explore Horses and Ponies · Ranger, Stop 1.2 (Ages 10–13) · Explore Horses and Ponies, Stop 1.2 (Ages 7–9)

disruptive colorationEnglish
Bold patches or stripes that break up an animal’s outline so the eye cannot find its true shape.
Explore Animals · Expert, Stop 6.2 (Ages 14+) · Grade 6 Life Science: Animal Design and Behavior, Lesson 4.1 (grade 6)

disruptive patternEnglish
Bold spots, stripes or patches that break up an animal’s outline so the eye does not see its true shape.
Explore Animals · Ranger, Stop 6.2 (Ages 10–13)

DissenterEnglish
In England after 1662, a Protestant who would not conform to the Church of England and worshiped in separate congregations.
Explore Heroines of History and Faith · Ranger, Stop 3.7 (Ages 10–13)

distaffEnglish
A staff that holds a bundle of prepared fiber while a spinner draws it out to twist into thread.
Explore Crafts and Making · Ranger, Stop 2.1 (Ages 10–13) · Explore Hospitality and Home · Ranger, Stop 4.1 (Ages 10–13) · Explore Hospitality and Home, Stop 4.1 (Ages 7–9) · +2 more

Distinguished Flying CrossEnglish
A U.S. award for heroism or extraordinary achievement in flight. Earhart was the first woman to receive it.
Explore Travel and Faraway Places · Ranger, Stop 3.8 (Ages 10–13)

dive bomberEnglish
A plane that dives steeply at its target and releases a bomb at low height; the American SBD Dauntless was the decisive plane at Midway.
Explore Great Battles · Expert, Stop 5.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.5 (Ages 10–13) · Explore Great Battles, Stop 5.5 (Ages 7–9)

division of labourEnglish
Adam Smith’s term (1776) for splitting work into specialties, so that each worker or trade concentrates on what it does best and trades for the rest.
Explore Crafts and Making · Expert, Stop 4.2 (Ages 14+)

dodoEnglish
A large bird that could not fly. It lived on an island in the Indian Ocean and went extinct about 350 years ago.
Explore Dinosaurs, Stop 4.7 (Ages 7–9)

DohnavurEnglish
A village in South India where Amy made a home for children.
Explore Heroines of History and Faith, Stop 4.5 (Ages 7–9)

Dohnavur FellowshipEnglish
The community Carmichael led at Dohnavur, a village in Tirunelveli, where rescued children were raised as a large family, with homes, a school and later a hospital.
Explore Heroines of History and Faith · Expert, Stop 4.5 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 4.5 (Ages 10–13)

domedEnglish
A rounded, high-backed shell that covers the neck closely. Common on higher, wetter islands with ground plants.
Explore Animals · Expert, Stop 3.6 (Ages 14+)

domesticEnglish
Tamed and bred by people to live and work with them, like dogs, horses and sheep.
Explore Animals · Ranger, Stop 1.6 (Ages 10–13)

dominionEnglish
The rule God gave people over the animals (Genesis 1:28), to be used wisely and kindly.
Explore Horses and Ponies, Stop 4.3 (Ages 7–9) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 8.4 (grade 4) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 7.1 (grade 8)

DomrémyEnglish
Joan’s village in eastern France (say “dom-ray-MEE”).
Explore Heroines of History and Faith, Stop 2.8 (Ages 7–9)

door-to-door timeEnglish
The whole time from leaving where you start to arriving where you stay, including waiting, security, transfers and baggage, not just time moving.
Explore Travel and Faraway Places · Expert, Stop 2.2 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 2.2 (Ages 10–13)

dormancyEnglish
A resting state in which an animal is inactive and uses little energy; bears are said to be dormant in winter.
Explore Animals · Ranger, Stop 6.3 (Ages 10–13)

dorsal vertebraEnglish
A backbone from the trunk, between the neck and the hips.
Explore Dinosaurs · Expert, Stop 1.10 (Ages 14+)

double countingEnglish
Counting the same individual bird more than once, the most common error in bird counts.
Explore Animals · Expert, Stop 2.10 (Ages 14+)

double elephant folioEnglish
One of the largest sizes of paper used for printed books, about 39½ by 29½ inches; chosen by Audubon to show birds life-size.
Explore Animals · Expert, Stop 2.9 (Ages 14+)

double envelopmentEnglish
A maneuver in which both wings of an army close around an enemy from two sides at once, trapping it. Marathon is one of the earliest recorded examples.
Explore Great Battles · Expert, Stop 1.1 (Ages 14+) · Explore Great Battles · Expert, Stop 1.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 1.1 (Ages 10–13) · +2 more

double monasteryEnglish
A monastery with separate houses for men and for women under one head; common in early Anglo-Saxon England and often ruled by an abbess.
Explore Heroines of History and Faith · Expert, Stop 2.5 (Ages 14+)

double-fold hemEnglish
A hem folded twice so the raw edge is hidden inside the fold.
Explore Crafts and Making · Expert, Stop 1.6 (Ages 14+) · Fabrics & Sewing I, Lesson 7.1 (grade 3–5) · Textile Science & Clothing Construction, Lesson 9.2 (grade 9–12)

Dowding systemEnglish
The network of radar, the Observer Corps, telephone lines, filter rooms and sector controllers that told Fighter Command where to send its squadrons.
Explore Great Battles · Expert, Stop 5.4 (Ages 14+)

draft horseEnglish
A heavy horse bred to pull loads, usually 16 to 19 hands and 1,600 to 2,200 pounds or more, with a broad chest, short strong back and powerful hindquarters. British spelling: draught.
Explore Horses and Ponies · Expert, Stop 1.4 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.4 (Ages 10–13) · Explore Horses and Ponies, Stop 1.4 (Ages 7–9) · +1 more

draglineEnglish
The strong safety line a spider trails behind it and uses for the frame and spokes of a web.
Explore Animals · Expert, Stop 5.4 (Ages 14+) · Grade 6 Life Science: Animal Design and Behavior, Lesson 5.2 (grade 6)

dragonEnglish
A great scaly creature with a long tail found in old stories all over the world. The King James Bible also uses the word.
Explore Dinosaurs, Stop 4.6 (Ages 7–9)

dragonflyEnglish
An insect with a long thin body, big eyes and four strong clear wings that hunts other insects in the air.
Explore Animals, Stop 5.7 (Ages 7–9)

drawstringEnglish
A cord threaded through a casing that pulls an opening closed.
Explore Crafts and Making · Ranger, Stop 1.6 (Ages 10–13) · Explore Crafts and Making, Stop 1.6 (Ages 7–9) · Fabrics & Sewing I, Lesson 4.3 (grade 3–5) · +1 more

dressEnglish
In the KJV, to prepare meat for cooking and serving.
Explore Hospitality and Home · Expert, Stop 3.2 (Ages 14+)

dressageEnglish
From the French for “training”: the art of developing a horse’s balance, suppleness and obedience, shown in tests of set movements scored by judges.
Explore Horses and Ponies · Expert, Stop 2.8 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.8 (Ages 10–13) · Explore Horses and Ponies, Stop 2.8 (Ages 7–9)

dromaeosaurEnglish
A member of the family of small to medium feathered theropods with a large curved claw on the second toe, including Velociraptor, Deinonychus and Utahraptor; often called “raptors.”
Explore Dinosaurs · Expert, Stop 1.5 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.5 (Ages 10–13)

dry and liquid measuresEnglish
Dry cups are filled to the brim and leveled; a liquid cup has a spout and lines below the rim and is read at eye level on a flat counter.
Explore Hospitality and Home · Expert, Stop 1.2 (Ages 14+)

duchessEnglish
A woman who rules a duchy in her own right, or the wife of a duke.
Explore Heroines of History and Faith · Ranger, Stop 2.7 (Ages 10–13) · Explore Heroines of History and Faith, Stop 2.7 (Ages 7–9)

Duke of ParmaEnglish
Alexander Farnese, Philip II’s governor and general in the Spanish Netherlands, whose veteran army the Armada was meant to escort across the Channel to England.
Explore Heroines of History and Faith · Expert, Stop 3.3 (Ages 14+)

Duke of WellingtonEnglish
Arthur Wellesley, the British general who commanded the allied army at Waterloo.
Explore Horses and Ponies · Ranger, Stop 3.3 (Ages 10–13) · Explore Horses and Ponies, Stop 3.3 (Ages 7–9)

DunfermlineEnglish
The royal town in Fife where Margaret married Malcolm and founded a priory with Benedictine monks from Canterbury.
Explore Heroines of History and Faith · Expert, Stop 2.6 (Ages 14+) · Explore Heroines of History and Faith, Stop 2.6 (Ages 7–9)

Durham boatEnglish
A long, flat-bottomed river freight boat, up to about 60 feet long, used to carry Washington’s infantry across the Delaware.
Explore Great Battles · Expert, Stop 3.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 3.5 (Ages 10–13) · Tactics & Strategy, Lesson 5.3 (grade 4–7)

Dutch resistanceEnglish
The many ordinary Dutch people who secretly worked against the German occupiers: hiding people, forging papers, sharing news and sabotaging the war effort.
Explore Heroines of History and Faith · Expert, Stop 4.7 (Ages 14+)

dutyEnglish
What you ought to do because it is right and it is your job, even when it is hard.
Explore Great Battles, Stop 3.8 (Ages 7–9) · Explore Travel and Faraway Places · Ranger, Stop 2.6 (Ages 10–13)

duty-free exemptionEnglish
The value of goods a returning traveler may bring home without paying duty; for most U.S. residents, $800 per person.
Explore Travel and Faraway Places · Expert, Stop 2.6 (Ages 14+)

dysenteryEnglish
A serious sickness of the gut, spread by bad water and food, which killed many soldiers in camps.
Explore Great Battles · Ranger, Stop 2.5 (Ages 10–13)

eared sealEnglish
A sea lion or fur seal (family Otariidae), with small outer ear flaps, long front flippers for swimming, and hind flippers that turn forward so it can walk on land.
Explore Animals · Expert, Stop 4.9 (Ages 14+) · Explore Animals · Ranger, Stop 4.9 (Ages 10–13)

easeEnglish
Extra room added to body measurements so a garment can be moved in (wearing ease) or to create a style (design ease).
Explore Crafts and Making · Expert, Stop 1.7 (Ages 14+) · Fabrics & Sewing I, Lesson 8.1 (grade 3–5) · Fabrics & Sewing II, Lesson 8.2 (grade 6–8) · +1 more

East India CompanyEnglish
The English (later British) trading company, chartered in 1600, that held the monopoly on importing tea from Asia to Britain for most of two centuries.
Explore Hospitality and Home · Expert, Stop 2.8 (Ages 14+)

easy keeperEnglish
An animal that stays fat on little food. It is a gift on a windswept island and a danger on rich pasture, where ponies easily grow obese and develop laminitis, a painful hoof disease.
Explore Horses and Ponies · Expert, Stop 1.6 (Ages 14+)

ectothermEnglish
An animal whose body heat comes mainly from its surroundings rather than from burning food. Reptiles bask to warm up and seek shade or water to cool down.
Explore Animals · Expert, Stop 3.1 (Ages 14+) · Explore Animals · Ranger, Stop 3.1 (Ages 10–13) · Explore Dinosaurs · Expert, Stop 3.6 (Ages 14+) · +3 more

EcuadorEnglish
A country on the west coast of South America, on the equator, with the high Andes mountains in the middle and the Amazon rainforest in the east.
Explore Heroines of History and Faith · Ranger, Stop 4.8 (Ages 10–13) · Explore Heroines of History and Faith, Stop 4.8 (Ages 7–9)

Edgar ÆthelingEnglish
Margaret’s brother, the last male of the old English royal house of Wessex; chosen king by some English leaders after Hastings but never crowned.
Explore Heroines of History and Faith · Expert, Stop 2.6 (Ages 14+)

Edict of MilanEnglish
The agreement of 313 between Constantine and Licinius granting Christians and all others freedom of worship and the return of seized church property.
Explore Heroines of History and Faith · Expert, Stop 2.2 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.2 (Ages 10–13)

eggshell porosityEnglish
How many and how large the pores are in a shell; it controls how quickly oxygen, carbon dioxide and water vapor pass through.
Explore Dinosaurs · Expert, Stop 3.2 (Ages 14+)

EgyptologyEnglish
The study of ancient Egypt’s history, language and remains. It grew quickly after Napoleon’s expedition of 1798 and the decoding of hieroglyphs in 1822.
Explore Travel and Faraway Places · Expert, Stop 4.6 (Ages 14+)

Eiffel TowerEnglish
A tall iron tower in Paris, built in 1887–1889 by Gustave Eiffel’s company.
Explore Travel and Faraway Places, Stop 4.4 (Ages 7–9)

Eighth ArmyEnglish
The British and Commonwealth army in North Africa, commanded at El Alamein by Lieutenant General Bernard Montgomery.
Explore Great Battles · Expert, Stop 5.6 (Ages 14+) · Explore Great Battles · Ranger, Stop 5.6 (Ages 10–13) · Explore Great Battles, Stop 5.6 (Ages 7–9)

elasmosaurEnglish
A plesiosaur with an extremely long neck and a small head. Elasmosaurus had 72 neck vertebrae.
Explore Dinosaurs · Expert, Stop 5.2 (Ages 14+)

EliEnglish
The high priest at Shiloh.
Explore Heroines of History and Faith, Stop 1.5 (Ages 7–9)

Elizabeth IEnglish
Queen of England from 1558 to 1603.
Explore Heroines of History and Faith, Stop 3.3 (Ages 7–9)

elytraEnglish
A beetle’s hardened front wings, which meet in a straight line down the back and cover and protect the folded flying wings beneath (singular: elytron).
Explore Animals · Expert, Stop 5.5 (Ages 14+) · Explore Animals · Ranger, Stop 5.5 (Ages 10–13) · Grade 6 Life Science: Animal Design and Behavior, Lesson 1.3 (grade 6)

embassy and consulateEnglish
A nation’s official offices in a foreign country (the embassy in the capital, consulates in other cities) that help their citizens in trouble, such as a lost passport or an arrest.
Explore Travel and Faraway Places · Expert, Stop 2.8 (Ages 14+)

embroideryEnglish
Decoration stitched with thread onto cloth. The Bayeux “Tapestry” is really an embroidery: colored wool stitched onto linen, not woven on a loom.
Explore Great Battles · Expert, Stop 2.2 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.2 (Ages 10–13) · Explore Crafts and Making · Expert, Stop 2.5 (Ages 14+) · +3 more

embryonic diapauseEnglish
A pause in the growth of a very early embryo. A kangaroo mother can keep a tiny embryo “on hold” until the joey in her pouch is ready to leave.
Explore Animals · Expert, Stop 1.9 (Ages 14+)

emergencyEnglish
A serious problem that needs help right away.
Explore Travel and Faraway Places, Stop 2.8 (Ages 7–9)

emergency numberEnglish
The short phone number that calls police, fire or ambulance, such as 911 in the United States.
Explore Travel and Faraway Places · Ranger, Stop 2.8 (Ages 10–13)

emeryEnglish
A hard, gritty mineral powder; a small cushion filled with it cleans and sharpens needles pushed through it.
Explore Crafts and Making · Expert, Stop 1.5 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 1.5 (Ages 10–13) · Explore Crafts and Making, Stop 1.5 (Ages 7–9)

emperorEnglish
The ruler of the Roman Empire.
Explore Heroines of History and Faith, Stop 2.1 (Ages 7–9)

encircleEnglish
To surround an enemy force on all sides.
Explore Great Battles · Ranger, Stop 5.8 (Ages 10–13)

encircledEnglish
Surrounded on all sides, as Bastogne was from December 20–21 to December 26, 1944.
Explore Great Battles · Expert, Stop 5.8 (Ages 14+)

endemicEnglish
Found naturally in only one place. The Komodo dragon is endemic to a few islands of eastern Indonesia.
Explore Animals · Expert, Stop 3.2 (Ages 14+) · Explore Animals · Ranger, Stop 3.5 (Ages 10–13)

endocastEnglish
A cast of the inside of the braincase, showing the size and shape of the space the brain filled.
Explore Dinosaurs · Expert, Stop 1.3 (Ages 14+)

endothermEnglish
An animal that makes most of its body heat from its own metabolism and keeps a steady temperature, such as birds and mammals.
Explore Dinosaurs · Expert, Stop 3.6 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 3.6 (Ages 10–13)

enduranceEnglish
The strength to keep going for a long time.
Explore Horses and Ponies, Stop 1.2 (Ages 7–9) · Grade 2 Physical Education & Health, Lesson 5.2 (grade 2) · Grade 3 Physical Education & Health, Lesson 5.2 (grade 3) · +2 more

endurance ridingEnglish
A sport of long-distance races, commonly 50 or 100 miles in a day, with veterinary checks along the way. Arabians and Arabian crosses dominate it.
Explore Horses and Ponies · Expert, Stop 1.2 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.2 (Ages 10–13)

enfiladeEnglish
Fire along the length of an enemy line from the side, the most dangerous fire a line can receive.
Explore Great Battles · Expert, Stop 4.7 (Ages 14+) · Explore Great Battles · Expert, Stop 5.2 (Ages 14+)

English ChannelEnglish
The narrow sea between England and France.
Explore Great Battles, Stop 5.3 (Ages 7–9) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 3.5 (grade 9–12) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 5.4 (grade 8)

English ridingEnglish
The European tradition of riding with a light saddle without a horn, direct contact on two reins held in two hands, and the posting trot; used in dressage, jumping, eventing and hunting.
Explore Horses and Ponies · Expert, Stop 2.8 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.8 (Ages 10–13) · Explore Horses and Ponies, Stop 2.8 (Ages 7–9)

engraving and aquatintEnglish
Printmaking methods in which lines are cut into a copper plate and tones are etched by acid through a grainy resin; the inked plate is pressed onto paper.
Explore Animals · Expert, Stop 2.9 (Ages 14+)

enlistmentEnglish
A soldier’s agreement to serve for a set time. In 1776 most Continental enlistments ran out on December 31.
Explore Great Battles · Expert, Stop 3.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 3.5 (Ages 10–13) · Explore Great Battles, Stop 3.5 (Ages 7–9) · +1 more

Enterprise of EnglandEnglish
Philip II’s name for his plan of 1588: a fleet from Spain would sail up the Channel and protect the crossing of the Duke of Parma’s army from Flanders to Kent.
Explore Great Battles · Expert, Stop 3.1 (Ages 14+)

entertainEnglish
In the King James Version, to receive someone and provide for him, as a host does for a guest. It does not mean “amuse.”
Explore Hospitality and Home · Expert, Stop 3.1 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 3.1 (Ages 10–13)

entomologistEnglish
A scientist who studies insects.
Explore Animals · Ranger, Stop 5.9 (Ages 10–13) · Explore Animals, Stop 5.9 (Ages 7–9)

entomologyEnglish
The scientific study of insects; an entomologist is a person who studies them.
Explore Animals · Expert, Stop 5.9 (Ages 14+) · Grade 8 Gardening & Animals, Lesson 8.2 (grade 8)

envelopeEnglish
A folded paper cover that holds a letter or card.
Explore Crafts and Making, Stop 3.4 (Ages 7–9)

epergneEnglish
An ornamental stand, usually silver or glass, with branching arms holding small dishes for fruit, sweets or flowers. Popular in Britain from the mid-1700s (say “ay-PURN”).
Explore Hospitality and Home · Expert, Stop 2.4 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.4 (Ages 10–13)

ephahEnglish
A dry measure of grain, roughly half a bushel. Ruth gleaned about an ephah of barley in one day (Ruth 2:17).
Explore Heroines of History and Faith · Expert, Stop 1.4 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 1.4 (Ages 10–13)

episodic plotEnglish
A story told as a chain of fairly separate episodes, linked by one main character. Beauty’s series of owners gives the book this shape.
Explore Horses and Ponies · Expert, Stop 4.2 (Ages 14+)

epitaphEnglish
Words written on a tomb or monument to remember the dead.
Explore Great Battles · Ranger, Stop 1.2 (Ages 10–13) · Grade 6 Greek, Lesson 2.2 (grade 6) · Grade 7 Greek, Lesson 2.2 (grade 7)

EpworthEnglish
The village in England where the Wesleys lived.
Explore Heroines of History and Faith, Stop 3.7 (Ages 7–9)

Epworth rectoryEnglish
The parsonage at Epworth where the Wesley children grew up. It burned in 1709 and was rebuilt, and the rebuilt house still stands.
Explore Heroines of History and Faith · Expert, Stop 3.7 (Ages 14+)

equal-area projectionEnglish
A projection that keeps every region at its true size compared with others, but bends and squashes shapes.
Explore Travel and Faraway Places · Expert, Stop 1.1 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 1.1 (Ages 10–13) · Geopolitics: The Great Ideas, Lesson 1.4 (grade 9–12)

equatorEnglish
The imaginary line around the middle of the earth, halfway between the poles, at 0° latitude.
Explore Travel and Faraway Places · Ranger, Stop 1.3 (Ages 10–13) · Explore Travel and Faraway Places, Stop 1.3 (Ages 7–9) · Grade 1 Geography: Maps and Journeys, Lesson 5.1 (grade 1) · +3 more

escaEnglish
The glowing “bait” at the tip of an anglerfish’s fishing rod (the illicium), a modified fin spine. In many species bacteria living inside it make the light.
Explore Animals · Expert, Stop 4.7 (Ages 14+)

espousedEnglish
Betrothed, or promised in marriage. In Jewish custom betrothal was a binding agreement, usually about a year before the wedding.
Explore Heroines of History and Faith · Ranger, Stop 1.8 (Ages 10–13)

essentialsEnglish
Things that would stop the trip if lost and cannot easily be replaced: travel documents, medicine, money and cards, glasses, keys and phone.
Explore Travel and Faraway Places · Expert, Stop 2.5 (Ages 14+) · Explore Travel and Faraway Places, Stop 2.5 (Ages 7–9)

Estes ParkEnglish
A high mountain valley in northern Colorado, now the gateway to Rocky Mountain National Park, where Isabella Bird stayed in a log cabin.
Explore Travel and Faraway Places · Ranger, Stop 3.6 (Ages 10–13)

EusebiusEnglish
Bishop of Caesarea and church historian who knew Constantine and wrote about Helena’s journey.
Explore Heroines of History and Faith · Ranger, Stop 2.2 (Ages 10–13)

evacuationEnglish
Moving people out of a dangerous place to safety.
Explore Great Battles · Ranger, Stop 5.3 (Ages 10–13) · Explore Great Battles, Stop 5.3 (Ages 7–9)

even-weaveEnglish
Fabric with the same number of threads per inch in both directions, so counted stitches come out square.
Explore Crafts and Making · Expert, Stop 2.6 (Ages 14+)

excursionEnglish
A short trip or outing, often arranged for a group at a set price.
Explore Travel and Faraway Places · Ranger, Stop 2.3 (Ages 10–13)

excuseEnglish
A reason given for not doing something. In Luke 14 the guests “make excuse” after they had already been invited.
Explore Hospitality and Home · Expert, Stop 3.4 (Ages 14+)

excuse meEnglish
Polite words to ask permission to leave or to say sorry.
Explore Hospitality and Home, Stop 2.6 (Ages 7–9)

exendin-4English
A peptide found in Gila monster venom that acts like human GLP-1 but lasts for hours instead of minutes in the body.
Explore Animals · Expert, Stop 3.10 (Ages 14+)

exhaust manifoldEnglish
The pipes that carry hot gases away from an engine’s cylinders; a cracked weld in Earhart’s showed flames during the night.
Explore Travel and Faraway Places · Expert, Stop 3.8 (Ages 14+)

exhibitEnglish
A display in a museum that teaches one main idea using objects, pictures and words.
Explore Dinosaurs · Ranger, Stop 5.10 (Ages 10–13) · Grade 3 Gardening & Animals, Lesson 7.1 (grade 3) · Grade 4 Gardening & Animals, Lesson 7.3 (grade 4) · +3 more

exileEnglish
Being forced to live away from one’s homeland.
Explore Heroines of History and Faith · Ranger, Stop 2.6 (Ages 10–13)

ExodusEnglish
The second book of the Bible, which tells how God brought Israel out of slavery in Egypt. The word means “a going out.”
Explore Horses and Ponies · Ranger, Stop 3.2 (Ages 10–13)

Exposition UniverselleEnglish
A world’s fair; the 1889 fair in Paris was the reason the Eiffel Tower was built.
Explore Travel and Faraway Places · Ranger, Stop 4.4 (Ages 10–13)

Exposition Universelle (1889)English
The World’s Fair held in Paris in 1889, marking the hundredth anniversary of the French Revolution; the Eiffel Tower was its entrance arch and centerpiece.
Explore Travel and Faraway Places · Expert, Stop 4.4 (Ages 14+)

expressEnglish
Fast, direct delivery of letters or goods.
Explore Horses and Ponies · Ranger, Stop 3.4 (Ages 10–13)

extant phylogenetic bracketEnglish
Inferring a feature of an extinct animal by checking its closest living relatives on either side (for dinosaurs: crocodilians and birds).
Explore Dinosaurs · Expert, Stop 3.10 (Ages 14+)

extensor musclesEnglish
The leg muscles that straighten the joints and push the body forward and up in each step.
Explore Dinosaurs · Expert, Stop 3.5 (Ages 14+)

extinctEnglish
No longer living anywhere on earth. The Carolina parakeet became extinct in the early 1900s.
Explore Animals · Ranger, Stop 2.6 (Ages 10–13) · Explore Dinosaurs · Ranger, Stop 4.7 (Ages 10–13) · Explore Dinosaurs, Stop 4.7 (Ages 7–9)

extinctionEnglish
The dying out of a whole kind of animal or plant. Around 1800 many people doubted it could happen; fossils like Anning’s helped settle the question.
Explore Dinosaurs · Expert, Stop 2.1 (Ages 14+) · Explore Dinosaurs · Expert, Stop 4.7 (Ages 14+) · Explore Dinosaurs · Expert, Stop 5.8 (Ages 14+) · +1 more

Fabian strategyEnglish
The policy of Quintus Fabius Maximus: avoid a pitched battle with a superior general, harass him and wear him down over time. It is named for Fabius, called “the Delayer.”
Explore Great Battles · Expert, Stop 1.5 (Ages 14+) · Explore Great Battles · Ranger, Stop 1.5 (Ages 10–13) · Tactics & Strategy, Lesson 5.2 (grade 4–7) · +2 more

facial discEnglish
The round or heart-shaped dish of stiff feathers around an owl’s face, which gathers sound and funnels it toward the ears.
Explore Animals · Expert, Stop 2.2 (Ages 14+) · Explore Animals · Ranger, Stop 2.2 (Ages 10–13) · Grade 4 Gardening & Animals, Lesson 2.2 (grade 4)

facial diskEnglish
The round, dish-shaped face of an owl that gathers sound to its ears.
Explore Animals, Stop 2.2 (Ages 7–9)

faienceEnglish
Ancient Egyptian glazed ceramic made from crushed quartz, shaped into beads and amulets and fired to a glossy blue-green.
Explore Crafts and Making · Expert, Stop 3.8 (Ages 14+)

faithEnglish
Trusting God and doing what He says, even before you can see how it will turn out.
Explore Travel and Faraway Places, Stop 3.1 (Ages 7–9)

Faithful and TrueEnglish
The name given to the rider on the white horse in Revelation 19:11, identified in the same chapter as the Word of God and King of kings.
Explore Horses and Ponies · Expert, Stop 3.2 (Ages 14+)

family styleEnglish
Serving dishes are set on the table and passed from hand to hand, so each person helps himself. The usual way of serving in most homes.
Explore Hospitality and Home · Expert, Stop 2.2 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.7 (Ages 10–13)

farewellEnglish
Goodbye.
Explore Hospitality and Home, Stop 3.5 (Ages 7–9)

farrierEnglish
A craftsman who trims horses’ hooves and fits horseshoes.
Explore Animals · Ranger, Stop 1.5 (Ages 10–13) · Explore Horses and Ponies · Expert, Stop 2.4 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.4 (Ages 10–13) · +3 more

fascineEnglish
A tight bundle of sticks or cane carried by attackers to fill a ditch so they can cross it.
Explore Great Battles · Expert, Stop 4.2 (Ages 14+)

fat reserveEnglish
Food energy stored in the body for later. A Gila monster stores fat in its thick tail.
Explore Animals · Ranger, Stop 3.10 (Ages 10–13)

fault (show jumping)English
A penalty in show jumping: 4 faults for a knocked-down rail or a first refusal, plus time faults for going over the time allowed.
Explore Horses and Ponies · Expert, Stop 2.8 (Ages 14+)

fearfullyEnglish
In Psalm 139:14, with awe and reverence; a thing so wonderful that it fills the one who sees it with holy wonder.
Explore Dinosaurs · Ranger, Stop 4.10 (Ages 10–13)

feed dogsEnglish
Toothed metal bars under the presser foot that move the fabric forward one stitch at a time.
Explore Crafts and Making · Expert, Stop 1.8 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 1.8 (Ages 10–13) · Fabrics & Sewing I, Lesson 4.1 (grade 3–5) · +1 more

feeding buzzEnglish
The rapid burst of calls, up to roughly 200 per second, a bat makes in the last moment before it catches an insect.
Explore Animals · Expert, Stop 6.1 (Ages 14+)

feeding envelopeEnglish
The whole space an animal can reach with its mouth without moving its feet.
Explore Dinosaurs · Expert, Stop 3.9 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 3.9 (Ages 10–13)

feigned flightEnglish
A pretended retreat meant to draw the enemy out of a strong position so that he can be attacked in the open. Norman and Breton horsemen were known for it.
Explore Great Battles · Expert, Stop 2.2 (Ages 14+)

feigned retreatEnglish
A pretended running away, meant to draw the enemy out of a strong position so it can be attacked.
Explore Great Battles · Ranger, Stop 2.2 (Ages 10–13) · Explore Great Battles, Stop 2.2 (Ages 7–9) · Tactics & Strategy, Lesson 4.2 (grade 4–7) · +1 more

feltEnglish
A thick cloth made by pressing wool or other fibers together. Its edges do not fray.
Explore Crafts and Making, Stop 1.5 (Ages 7–9) · Fabrics & Sewing I, Lesson 2.4 (grade 3–5) · Threads & Weaving, Lesson 3.3 (grade 9–12)

femurEnglish
The thighbone, between the hip and the knee.
Explore Dinosaurs · Ranger, Stop 1.4 (Ages 10–13) · Grade 6 Life Science: Animal Design and Behavior, Lesson 7.3 (grade 6)

fenEnglish
An old English word for marshy, wet ground with reeds (Job 40:21).
Explore Dinosaurs · Ranger, Stop 4.2 (Ages 10–13)

feralEnglish
Living wild but descended from domestic animals. The Assateague horses are feral, not truly wild.
Explore Horses and Ponies · Expert, Stop 1.7 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.7 (Ages 10–13)

Fertile CrescentEnglish
The arc of watered land curving from the Persian Gulf up the Tigris and Euphrates, across Syria and down to Canaan and Egypt, with desert inside the curve.
Explore Travel and Faraway Places · Expert, Stop 3.1 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.1 (Ages 10–13) · Grade 7 Geography: Regions of the World, Lesson 3.1 (grade 7) · +1 more

fertility controlEnglish
In the Maryland herd, a vaccine given to mares by dart (since 1994) that prevents pregnancy for a time, keeping numbers steady without roundups.
Explore Horses and Ponies · Expert, Stop 1.7 (Ages 14+)

fetlockEnglish
The round joint just above the pastern and hoof, sometimes called the ankle; it often has a tuft of hair behind it.
Explore Horses and Ponies · Ranger, Stop 2.1 (Ages 10–13) · Explore Horses and Ponies, Stop 2.1 (Ages 7–9)

fetlock and pasternEnglish
The fetlock is the ball-shaped joint above the hoof (the horse’s knuckle); the pastern is the short, sloping section between the fetlock and the hoof (the horse’s finger bones).
Explore Horses and Ponies · Expert, Stop 2.1 (Ages 14+)

fiber contentEnglish
The kinds and percentages of fibers in a textile, such as “100% cotton” or “80% wool, 20% nylon.” U.S. law requires it on most textile products offered for sale.
Explore Crafts and Making · Expert, Stop 4.6 (Ages 14+)

fibrolamellar boneEnglish
A fast-growing, spongy-looking bone tissue packed with blood vessels, common in birds and mammals and in many dinosaurs.
Explore Dinosaurs · Expert, Stop 3.6 (Ages 14+)

fibulaEnglish
The thinner of the two bones of the lower leg.
Explore Dinosaurs · Expert, Stop 1.10 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.10 (Ages 10–13)

fictionEnglish
A made-up story.
Explore Horses and Ponies, Stop 4.5 (Ages 7–9)

field jacketEnglish
A protective shell of burlap strips soaked in plaster, wrapped around a fossil and the rock holding it before it is moved.
Explore Dinosaurs · Expert, Stop 2.7 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 2.7 (Ages 10–13) · Explore Dinosaurs, Stop 2.7 (Ages 7–9)

field markEnglish
A visible feature that helps identify a bird, such as a wing bar, eye ring, bill shape or tail pattern.
Explore Animals · Expert, Stop 2.10 (Ages 14+) · Grade 2 Gardening & Animals, Lesson 2.1 (grade 2) · Grade 5 Gardening & Animals, Lesson 2.2 (grade 5) · +3 more

field marksEnglish
The colors, patterns and shapes that help tell one kind of bird from another, such as a wing bar, an eye ring or a crest.
Explore Animals · Ranger, Stop 2.10 (Ages 10–13) · Explore Animals, Stop 2.10 (Ages 7–9)

filigreeEnglish
From Latin filum (thread) and granum (grain): delicate openwork made of fine twisted wire, usually silver or gold. Paper filigree imitated it, and in Jane Austen’s England quilling was simply called “filigree.”
Explore Crafts and Making · Expert, Stop 3.5 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 3.5 (Ages 10–13) · Explore Crafts and Making, Stop 3.5 (Ages 7–9)

fillyEnglish
A young female horse, usually under four years old.
Explore Horses and Ponies · Ranger, Stop 4.4 (Ages 10–13)

filter feederEnglish
An animal that strains tiny food, such as plankton, out of the water. The whale shark is one.
Explore Animals · Ranger, Stop 4.1 (Ages 10–13)

findingsEnglish
The small metal parts that make jewelry work: clasps, jump rings, crimp beads, head pins, eye pins and ear wires.
Explore Crafts and Making · Expert, Stop 3.8 (Ages 14+)

fine mealEnglish
Finely ground flour, the best kind, used for offerings and for honored guests.
Explore Hospitality and Home · Expert, Stop 3.2 (Ages 14+)

finished positionEnglish
Fork and knife laid side by side across the plate, a signal that you have finished. In America the handles point to about 4 o’clock, as if the plate were a clock face.
Explore Hospitality and Home · Ranger, Stop 2.6 (Ages 10–13)

finished sizeEnglish
The size of an item after all seams and hems are sewn, as opposed to the cutting size.
Explore Crafts and Making · Expert, Stop 1.6 (Ages 14+)

finite element analysisEnglish
A computer method that divides a structure into many small parts to calculate how it bends or breaks under force.
Explore Dinosaurs · Expert, Stop 1.9 (Ages 14+)

firebreakEnglish
A gap cleared of anything that can burn, so a fire cannot cross it. In 1666 houses were pulled down or blown up with gunpowder to make firebreaks.
Explore Travel and Faraway Places · Expert, Stop 4.3 (Ages 14+)

fireflyEnglish
A kind of beetle that makes light in the back part of its body. Some people call it a lightning bug.
Explore Animals, Stop 5.6 (Ages 7–9)

fireshipEnglish
An old vessel loaded with tar, pitch and timber, set alight and sent with the wind and tide into an anchored fleet.
Explore Great Battles · Expert, Stop 3.1 (Ages 14+) · Explore Great Battles · Ranger, Stop 3.1 (Ages 10–13) · Explore Great Battles, Stop 3.1 (Ages 7–9) · +3 more

first impressionEnglish
The judgment people form in the first moments of meeting. Psychologists have found that people form some impressions of a face within a tenth of a second.
Explore Hospitality and Home · Expert, Stop 3.5 (Ages 14+)

First LadyEnglish
The title later given to the wife of the President of the United States. Abigail was the second, after Martha Washington.
Explore Heroines of History and Faith · Ranger, Stop 3.6 (Ages 10–13)

first-person narratorEnglish
A storyteller who speaks as “I” from inside the story. In Black Beauty the narrator is the horse himself.
Explore Horses and Ponies · Expert, Stop 4.1 (Ages 14+)

Firth of ForthEnglish
The wide inlet of the North Sea between Edinburgh and Fife in Scotland.
Explore Heroines of History and Faith · Ranger, Stop 2.6 (Ages 10–13)

fishEnglish
An animal that lives in water, breathes with gills and swims with fins.
Explore Animals, Stop 4.1 (Ages 7–9) · Grade 1 Life Science: Animal Homes and Habits, Lesson 3.4 (grade 1) · Grade 2 Life Science: Animal Families, Lesson 5.1 (grade 2)

fish ladderEnglish
A series of stepped pools or a channel built beside a dam so that migrating fish can swim and leap past it.
Explore Animals · Expert, Stop 4.8 (Ages 14+) · Explore Animals · Ranger, Stop 4.8 (Ages 10–13) · Explore Animals, Stop 4.8 (Ages 7–9) · +1 more

fishhook lineEnglish
The curved Union line at Gettysburg, from Culp’s Hill around Cemetery Hill and south along Cemetery Ridge to the Round Tops.
Explore Great Battles · Expert, Stop 4.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 4.7 (Ages 10–13)

Five FreedomsEnglish
A widely used checklist of animal welfare first set out in Britain in 1965 and later refined: freedom from hunger and thirst; from discomfort; from pain, injury and disease; to express normal behavior; and from fear and distress.
Explore Horses and Ponies · Expert, Stop 4.3 (Ages 14+)

flag signalEnglish
A message sent by hoisting numbered flags; in 1805 the Royal Navy used Sir Home Popham’s code, in which numbers stood for whole words.
Explore Great Battles · Expert, Stop 3.8 (Ages 14+)

flagshipEnglish
The ship carrying the admiral in command, flying his flag. Nelson’s flagship was HMS Victory.
Explore Great Battles · Ranger, Stop 3.8 (Ages 10–13)

Flaming CliffsEnglish
Andrews’ name for the red sandstone cliffs at Bayanzag (Shabarakh Usu) in Mongolia, where the eggs were found.
Explore Dinosaurs · Expert, Stop 2.8 (Ages 14+)

flankEnglish
The side or end of an army’s line, usually its weakest point. To “turn a flank” is to get around it.
Explore Great Battles · Expert, Stop 5.1 (Ages 14+) · Explore Great Battles · Ranger, Stop 1.1 (Ages 10–13) · Explore Great Battles · Ranger, Stop 5.1 (Ages 10–13) · +3 more

flank marchEnglish
A march around the side of the enemy’s line to attack it from the side or rear.
Explore Great Battles · Expert, Stop 4.4 (Ages 14+) · Explore Great Battles · Ranger, Stop 4.4 (Ages 10–13)

flash patternEnglish
The length, number, color and timing of a firefly’s flashes, which differ by species and act as a signal.
Explore Animals · Expert, Stop 5.6 (Ages 14+)

flat-foldableEnglish
Able to be pressed completely flat without tearing or adding creases. Maekawa’s and Kawasaki’s rules tell whether a single vertex is flat-foldable.
Explore Crafts and Making · Expert, Stop 3.2 (Ages 14+)

flatwareEnglish
Knives, forks and spoons for the table. Americans often say “silverware” even when the pieces are stainless steel; the British say “cutlery.”
Explore Hospitality and Home · Expert, Stop 2.1 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 2.1 (Ages 10–13) · Explore Hospitality and Home, Stop 2.1 (Ages 7–9)

Flavian AmphitheaterEnglish
The Colosseum’s ancient name, after the Flavian family of emperors (Vespasian, Titus and Domitian) who built it.
Explore Travel and Faraway Places · Ranger, Stop 4.2 (Ages 10–13)

Flavian AmphitheatreEnglish
The Colosseum’s ancient name, from the Flavian family of emperors (Vespasian, Titus and Domitian) who built it between about A.D. 70 and 90.
Explore Travel and Faraway Places · Expert, Stop 4.2 (Ages 14+)

flawEnglish
A mistake or weak spot in something you made.
Explore Crafts and Making, Stop 4.5 (Ages 7–9)

flaxEnglish
A plant with blue flowers whose long stem fibers are spun into linen thread.
Explore Hospitality and Home · Ranger, Stop 4.1 (Ages 10–13) · Fabrics & Sewing I, Lesson 1.3 (grade 3–5)

fledglingEnglish
A young bird that has just left the nest.
Explore Animals, Stop 2.8 (Ages 7–9)

fleeceEnglish
The whole coat of wool shorn from one sheep, which comes off in a single piece like a woolly rug.
Explore Crafts and Making · Ranger, Stop 2.1 (Ages 10–13) · Explore Crafts and Making, Stop 2.1 (Ages 7–9) · Grade 3 Gardening & Animals, Lesson 6.3 (grade 3) · +3 more

fleetEnglish
A group of warships.
Explore Great Battles, Stop 1.3 (Ages 7–9) · Explore Great Battles, Stop 3.1 (Ages 7–9) · Grade 3 Geography: Around the World: Continents and Oceans, Lesson 8.2 (grade 3) · +1 more

flexibilityEnglish
How freely travelers can change time, route or stops after setting out.
Explore Travel and Faraway Places · Expert, Stop 2.2 (Ages 14+) · Grade 10 Physical Education & Health, Lesson 1.2 (grade 10) · Grade 4 Physical Education & Health, Lesson 1.2 (grade 4) · +1 more

flight instinctEnglish
A horse’s built-in urge, as a prey animal, to run from anything sudden or strange before deciding whether it is dangerous.
Explore Horses and Ponies · Expert, Stop 3.1 (Ages 14+)

flight responseEnglish
A prey animal’s instinct to run first and think later when startled; a horse’s first defense is speed, its second is a kick or strike.
Explore Horses and Ponies · Expert, Stop 2.7 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.7 (Ages 10–13)

flightlessEnglish
Unable to fly in air. Penguins’ wings have become stiff flippers used to “fly” through water.
Explore Animals · Expert, Stop 2.4 (Ages 14+) · Explore Animals, Stop 2.5 (Ages 7–9)

flipEnglish
To turn food over with a spatula.
Explore Hospitality and Home, Stop 1.4 (Ages 7–9)

flipperEnglish
A penguin’s stiff, flat wing, used to “fly” through water instead of air.
Explore Animals · Ranger, Stop 2.4 (Ages 10–13) · Explore Animals, Stop 2.4 (Ages 7–9) · Explore Animals, Stop 3.4 (Ages 7–9) · +3 more

flockEnglish
A group of birds that live, feed or travel together.
Explore Animals · Ranger, Stop 2.6 (Ages 10–13) · Explore Animals, Stop 2.6 (Ages 7–9) · Grade 1 Gardening & Animals, Lesson 6.2 (grade 1) · +1 more

flossEnglish
Embroidery thread, usually six thin cotton strands loosely twisted together that can be separated.
Explore Crafts and Making · Ranger, Stop 2.5 (Ages 10–13) · Explore Crafts and Making, Stop 2.5 (Ages 7–9)

flower frogEnglish
A heavy holder with pins or holes that sits in the bottom of a bowl and holds stems upright.
Explore Hospitality and Home · Ranger, Stop 2.4 (Ages 10–13)

flukeEnglish
One of the two flat lobes of a whale’s tail. Whale tails are horizontal and beat up and down; fish tails are vertical and sweep side to side.
Explore Animals · Expert, Stop 1.3 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 5.3 (Ages 10–13)

flukesEnglish
The two horizontal lobes of a whale’s or dolphin’s tail, beaten up and down to swim.
Explore Animals · Expert, Stop 4.5 (Ages 14+)

flying gallopEnglish
The old way of painting a galloping horse with front legs stretched forward and back legs stretched behind, all off the ground at once. Muybridge’s photographs proved that real horses never hold that position.
Explore Horses and Ponies · Expert, Stop 4.8 (Ages 14+)

flywayEnglish
A broad route used by many migrating birds; North America has four: Atlantic, Mississippi, Central and Pacific.
Explore Animals · Expert, Stop 2.7 (Ages 14+) · Explore Animals · Ranger, Stop 2.7 (Ages 10–13) · Grade 3 Gardening & Animals, Lesson 2.4 (grade 3) · +1 more

foalEnglish
A baby horse.
Explore Animals, Stop 1.5 (Ages 7–9) · Explore Horses and Ponies, Stop 1.1 (Ages 7–9)

focal, filler and greeneryEnglish
The three roles in an arrangement: a few bold focal flowers, smaller filler flowers, and leaves or branches that give shape.
Explore Hospitality and Home · Expert, Stop 2.4 (Ages 14+)

fold diagramEnglish
A drawing that shows how to fold step by step, using dashed lines for creases and arrows for the direction to fold.
Explore Hospitality and Home · Ranger, Stop 2.3 (Ages 10–13)

folio, quarto, octavoEnglish
Sizes named for how many times a printed sheet is folded: once (folio, 2 leaves), twice (quarto, 4 leaves) or three times (octavo, 8 leaves).
Explore Crafts and Making · Expert, Stop 3.7 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 3.7 (Ages 10–13)

FontevraudEnglish
An abbey in the Loire valley, ruled by an abbess, where Eleanor spent her last years and was buried.
Explore Heroines of History and Faith · Expert, Stop 2.7 (Ages 14+)

food cacheEnglish
A pile of branches a beaver sinks in the pond mud near its lodge in autumn, to eat under the ice all winter.
Explore Animals · Expert, Stop 6.4 (Ages 14+) · Grade 6 Life Science: Animal Design and Behavior, Lesson 5.3 (grade 6)

foot pedalEnglish
The control on the floor that makes the machine go; press harder to go faster.
Explore Crafts and Making, Stop 1.8 (Ages 7–9) · Fabrics & Sewing I, Lesson 4.1 (grade 3–5)

foot washingEnglish
In Bible lands, giving water (or a servant’s help) to wash a guest’s dusty feet. It was the first courtesy at the door.
Explore Hospitality and Home · Ranger, Stop 3.5 (Ages 10–13)

foot-bindingEnglish
The old Chinese custom of tightly binding young girls’ feet to keep them small, which crippled them. The Chinese government had outlawed it, and Aylward was hired to inspect and enforce the ban.
Explore Heroines of History and Faith · Expert, Stop 4.6 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 4.6 (Ages 10–13)

footmanEnglish
A male servant in a large house who waited at table, carried dishes and answered the door, under the butler.
Explore Hospitality and Home · Expert, Stop 2.7 (Ages 14+)

footprintEnglish
The mark a foot leaves pressed into soft ground.
Explore Dinosaurs, Stop 3.3 (Ages 7–9) · Grade 1 Life Science: Animal Homes and Habits, Lesson 7.4 (grade 1)

forageEnglish
Grass and hay, the fiber-rich plant food that should make up most of every horse’s diet.
Explore Horses and Ponies · Expert, Stop 2.5 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.5 (Ages 10–13) · Explore Horses and Ponies · Ranger, Stop 4.3 (Ages 10–13) · +3 more

fordEnglish
A shallow place where soldiers, horses and wagons can wade across a stream.
Explore Great Battles · Ranger, Stop 4.4 (Ages 10–13) · Grade 4 Geography: The United States: Regions, Rivers and Routes, Lesson 5.2 (grade 4) · Grade 8 Geography: Rivers, Ports and Straits, Lesson 1.1 (grade 8)

forgiveEnglish
To let go of a wrong and not pay it back.
Explore Heroines of History and Faith, Stop 4.8 (Ages 7–9)

forked tongueEnglish
A tongue split into two tips at the end, used by snakes and some lizards to pick up smells.
Explore Animals, Stop 3.2 (Ages 7–9) · Grade 2 Life Science: Animal Families, Lesson 3.2 (grade 2)

formalEnglish
Fancy and careful, for special occasions.
Explore Hospitality and Home, Stop 2.2 (Ages 7–9)

formal invitationEnglish
An invitation written in the third person (“Mr. and Mrs. John Smith request the pleasure of …”), traditionally engraved or written in ink on a card, and answered in the same form.
Explore Hospitality and Home · Expert, Stop 3.4 (Ages 14+)

fortEnglish
A strong building made to defend a place.
Explore Great Battles, Stop 2.6 (Ages 7–9) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 7.4 (grade 2)

fortificationEnglish
A wall, ditch or tower built to defend a place.
Explore Great Battles, Stop 1.7 (Ages 7–9)

fortifyEnglish
To make a place stronger with walls, ditches or logs so it is easier to defend.
Explore Great Battles, Stop 3.6 (Ages 7–9)

fossil graveyardEnglish
A place where the bones of many animals are buried together in the rock.
Explore Dinosaurs, Stop 4.5 (Ages 7–9)

fossil hunterEnglish
A person who searches for fossils and digs them out carefully.
Explore Dinosaurs, Stop 2.1 (Ages 7–9)

fossilistEnglish
An old word for a person who collected, cleaned and sold fossils, often for a living.
Explore Dinosaurs · Expert, Stop 2.1 (Ages 14+)

fossorialEnglish
Adapted for living underground, in burrows.
Explore Animals · Expert, Stop 3.10 (Ages 14+)

foundation breedEnglish
A breed whose bloodlines were used to build or improve many later breeds.
Explore Horses and Ponies · Ranger, Stop 1.2 (Ages 10–13)

foundation sireEnglish
One of the stallions at the root of a breed. The Thoroughbred’s three are the Byerley Turk, the Darley Arabian and the Godolphin Arabian.
Explore Horses and Ponies · Expert, Stop 1.3 (Ages 14+) · Explore Horses and Ponies · Expert, Stop 4.6 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 1.3 (Ages 10–13) · +1 more

fourteenerEnglish
A mountain over 14,000 feet; Long’s Peak (14,259 feet) is the highest in Rocky Mountain National Park.
Explore Travel and Faraway Places · Expert, Stop 3.6 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.6 (Ages 10–13)

foveaEnglish
A small pit in the retina packed with light-sensing cones, where vision is sharpest; an eagle has two in each eye.
Explore Animals · Expert, Stop 2.1 (Ages 14+) · Explore Animals · Ranger, Stop 2.1 (Ages 10–13)

fragmentaryEnglish
Known from only a few pieces of the skeleton, so much of the animal must be estimated.
Explore Dinosaurs · Expert, Stop 1.10 (Ages 14+)

framework claimEnglish
A statement that depends on a larger view of history, such as a date in millions of years or a claim about ancestry (“evolved from”).
Explore Dinosaurs · Expert, Stop 4.8 (Ages 14+)

FranksEnglish
A people who lived in what is now France and Germany. France is named after them.
Explore Great Battles, Stop 2.1 (Ages 7–9) · Explore Heroines of History and Faith · Expert, Stop 2.4 (Ages 14+) · Explore Heroines of History and Faith · Ranger, Stop 2.4 (Ages 10–13) · +1 more

frayingEnglish
The unraveling of loose threads from a cut edge of woven fabric.
Explore Crafts and Making · Expert, Stop 1.6 (Ages 14+)

freewill offeringEnglish
A gift given gladly by choice, not by force or as a tax.
Explore Crafts and Making · Ranger, Stop 4.1 (Ages 10–13)

French and Indian WarEnglish
The war in North America (1754–1763) between Britain and France, with Indian nations fighting on both sides.
Explore Great Battles, Stop 3.3 (Ages 7–9)

French knotEnglish
A tiny knot that sits on top of the cloth like a bead, made by wrapping thread around the needle.
Explore Crafts and Making, Stop 2.5 (Ages 7–9) · Fabrics & Sewing I, Lesson 3.4 (grade 3–5)

French seamEnglish
A seam sewn twice, first wrong sides together and then right sides together, enclosing the raw edges inside.
Explore Crafts and Making · Expert, Stop 1.6 (Ages 14+) · Fabrics & Sewing I, Lesson 4.4 (grade 3–5) · Fabrics & Sewing II, Lesson 2.4 (grade 6–8) · +1 more

frequency (hertz)English
How many times a sound wave vibrates each second. One hertz (Hz) is one vibration per second; high-pitched sounds have high frequencies.
Explore Animals · Ranger, Stop 6.1 (Ages 10–13)

frillEnglish
The broad shelf of bone that sweeps back from a ceratopsian’s skull over the neck.
Explore Dinosaurs · Expert, Stop 1.2 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 1.2 (Ages 10–13) · Explore Dinosaurs, Stop 1.2 (Ages 7–9) · +2 more

fringing reefEnglish
A reef that grows right along the shore.
Explore Animals · Ranger, Stop 4.3 (Ages 10–13)

frogEnglish
The rubbery, V-shaped pad on the underside of the hoof that absorbs shock, gives grip and helps blood circulate in the foot.
Explore Horses and Ponies · Expert, Stop 2.4 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 2.4 (Ages 10–13) · Explore Horses and Ponies, Stop 2.4 (Ages 7–9) · +2 more

frogspawnEnglish
A mass of frog eggs held together in clear jelly.
Explore Animals · Ranger, Stop 3.7 (Ages 10–13) · Grade 2 Life Science: Animal Families, Lesson 8.3 (grade 2)

frontoparietal domeEnglish
The thick, rounded mass of bone on top of a pachycephalosaur skull, formed from the fused frontal and parietal bones.
Explore Dinosaurs · Expert, Stop 1.9 (Ages 14+)

Fugitive Slave ActEnglish
A law of 1850 that required people in the free Northern states to help return escaped people to slavery, so many had to go all the way to Canada to be safe.
Explore Heroines of History and Faith · Ranger, Stop 4.3 (Ages 10–13)

Fugitive Slave Act of 1850English
A federal law requiring officials and citizens in free states to help return escaped slaves, and denying the accused a jury trial. After it, no Northern state was truly safe.
Explore Heroines of History and Faith · Expert, Stop 4.3 (Ages 14+)

furlongEnglish
A racing distance of 220 yards, one-eighth of a mile (about 201 meters), from the old “furrow long” of a plowed field.
Explore Horses and Ponies · Expert, Stop 1.3 (Ages 14+) · Explore Horses and Ponies · Expert, Stop 3.8 (Ages 14+) · Explore Horses and Ponies · Ranger, Stop 3.7 (Ages 10–13)

fusedEnglish
Grown together into one solid piece. “Ankylosaurus” comes from the Greek word for fused or stiffened.
Explore Dinosaurs · Ranger, Stop 1.6 (Ages 10–13) · Explore Dinosaurs, Stop 1.6 (Ages 7–9)

fyrdEnglish
The English militia raised from the shires for a limited time of service; at Hastings it stood in the shield wall beside the housecarls.
Explore Great Battles · Expert, Stop 2.2 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.2 (Ages 10–13)

GabrielEnglish
An angel who brings messages from God.
Explore Heroines of History and Faith, Stop 1.8 (Ages 7–9)

gaitEnglish
A pattern of leg movement. The four natural gaits of most horses are the walk, trot, canter and gallop.
Explore Animals · Expert, Stop 1.5 (Ages 14+) · Explore Animals, Stop 1.5 (Ages 7–9) · Explore Horses and Ponies · Expert, Stop 2.6 (Ages 14+) · +3 more

Galápagos IslandsEnglish
A group of islands in the Pacific Ocean, about 600 miles west of South America, that belong to Ecuador (say “guh-LAH-puh-gus”).
Explore Animals, Stop 3.6 (Ages 7–9)

GalileeEnglish
The hilly northern land around a big freshwater lake, where Jesus grew up and taught.
Explore Travel and Faraway Places, Stop 4.1 (Ages 7–9)

galleassEnglish
A large, high-sided Venetian galley armed with many guns along its sides as well as at the bow and stern, like a floating fortress.
Explore Great Battles · Expert, Stop 2.8 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.8 (Ages 10–13) · Explore Great Battles, Stop 2.8 (Ages 7–9)

galleonEnglish
A large sailing warship with several decks of guns and high “castles” at the front and back, used by Spain, England and other nations in the 1500s and 1600s.
Explore Great Battles · Ranger, Stop 3.1 (Ages 10–13) · Explore Heroines of History and Faith · Ranger, Stop 3.3 (Ages 10–13) · Geography and Commerce: Sea Lanes, Straits and Trade Routes, Lesson 2.5 (grade 9–12)

galleyEnglish
A long, narrow warship driven by oars, with sails for cruising. It fought bow-first, with guns in the bow and soldiers who boarded the enemy ship.
Explore Great Battles · Expert, Stop 2.8 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.8 (Ages 10–13) · Explore Great Battles, Stop 2.8 (Ages 7–9) · +1 more

galley slaveEnglish
A rower forced to work the oars: a captive, a slave or a convict. Both fleets at Lepanto used them, though Venice also used paid free oarsmen.
Explore Great Battles · Expert, Stop 2.8 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.8 (Ages 10–13)

Gallio inscriptionEnglish
A letter of Emperor Claudius carved in stone at Delphi that dates Gallio’s time as governor of Achaia to about A.D. 51–52, fixing Paul’s stay in Corinth (Acts 18:12).
Explore Travel and Faraway Places · Expert, Stop 3.2 (Ages 14+)

gallopEnglish
The fastest gait, with four beats and a moment when all feet leave the ground.
Explore Horses and Ponies, Stop 2.6 (Ages 7–9)

gapEnglish
An open space or hole in a line.
Explore Great Battles, Stop 1.4 (Ages 7–9) · Grade 2 Geography: Our Country, Coast to Coast, Lesson 4.1 (grade 2) · Geography and History: Why Borders Fall Where They Do, Lesson 8.1 (grade 9–12) · +1 more

gapeEnglish
How wide the jaws can open, measured as an angle. Sabertooths needed a very wide gape to clear their long canines.
Explore Dinosaurs · Expert, Stop 5.7 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 5.7 (Ages 10–13)

garter stitchEnglish
Fabric made by knitting every row. It forms horizontal ridges (two rows make one ridge), lies flat and does not curl.
Explore Crafts and Making · Expert, Stop 2.3 (Ages 14+) · Explore Crafts and Making · Ranger, Stop 2.3 (Ages 10–13) · Explore Crafts and Making, Stop 2.4 (Ages 7–9) · +1 more

gastraliaEnglish
Belly ribs: thin bones in the wall of the belly, not joined to the backbone. SUE’s are complete enough to show how they fit.
Explore Dinosaurs · Expert, Stop 2.9 (Ages 14+)

gastrolithEnglish
A stone swallowed on purpose and kept in the stomach. Many plesiosaur skeletons contain piles of them; their use (ballast or grinding food) is still debated.
Explore Dinosaurs · Expert, Stop 5.2 (Ages 14+) · Explore Dinosaurs · Ranger, Stop 5.2 (Ages 10–13)

gaugeEnglish
A numbered scale for the thickness of wire. In the older wire gauges, a higher number meant wire drawn more times and therefore thinner.
Explore Crafts and Making · Expert, Stop 1.1 (Ages 14+) · Explore Crafts and Making · Expert, Stop 2.2 (Ages 14+) · Explore Crafts and Making · Expert, Stop 2.3 (Ages 14+) · +3 more

GaulEnglish
The old name for the land that is now France and nearby lands.
Explore Great Battles, Stop 1.7 (Ages 7–9) · Explore Heroines of History and Faith · Ranger, Stop 2.4 (Ages 10–13) · Grade 8 Latin, Lesson 4.2 (grade 8)

genealogyEnglish
A record of a family line. Ruth ends with one (Ruth 4:18–22), and Matthew 1:5 names Ruth in the line of Jesus.
Explore Heroines of History and Faith · Expert, Stop 1.4 (Ages 14+) · Grade 8 Life Science: Heredity, Design and Origins, Lesson 6.1 (grade 8)

generalEnglish
A high army leader.
Explore Horses and Ponies, Stop 3.5 (Ages 7–9)

General Stud BookEnglish
The official register of Thoroughbreds in Britain, begun by James Weatherby with an introductory volume in 1791 and kept by the Weatherby family firm ever since.
Explore Horses and Ponies · Expert, Stop 1.3 (Ages 14+)

generalizationEnglish
A mapmaker’s choice of what to simplify or leave out so that a map stays clear at its scale.
Explore Travel and Faraway Places · Expert, Stop 1.8 (Ages 14+)

genetic bottleneckEnglish
A time when a population becomes very small, leaving the survivors with little genetic variety. Cheetahs are unusually alike in their genes.
Explore Animals · Expert, Stop 1.8 (Ages 14+)

Geneva ConventionEnglish
A treaty first signed in 1864 in which nations agreed to protect wounded soldiers and the people caring for them, whatever side they were on.
Explore Heroines of History and Faith · Ranger, Stop 4.2 (Ages 10–13)

Geneva Convention (1864)English
A treaty in which nations agreed that wounded soldiers, and those who care for them under the red cross emblem, would be treated as neutral and protected in war.
Explore Heroines of History and Faith · Expert, Stop 4.2 (Ages 14+)

GentilesEnglish
People who are not Jews; the nations to whom Paul was especially sent.
Explore Travel and Faraway Places · Expert, Stop 3.2 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 3.2 (Ages 10–13)

gentlingEnglish
Teaching a wild or untrained horse to accept people by patience, routine and trust rather than force.
Explore Horses and Ponies · Expert, Stop 4.7 (Ages 14+)

Geography (Ptolemy’s)English
A Greek handbook written in Alexandria around A.D. 150 that taught how to draw maps from coordinates and listed thousands of places by latitude and longitude.
Explore Travel and Faraway Places · Expert, Stop 1.7 (Ages 14+)

geolocatorEnglish
A tiny tag that records light levels so scientists can later calculate where a bird was each day.
Explore Animals · Expert, Stop 6.7 (Ages 14+) · Explore Animals · Ranger, Stop 6.7 (Ages 10–13) · Grade 6 Life Science: Animal Design and Behavior, Lesson 2.1 (grade 6)

geological islandEnglish
The islands in the park’s lake where the models were grouped in the order of the rock layers in which their fossils were found.
Explore Dinosaurs · Expert, Stop 2.5 (Ages 14+)

geologyEnglish
The study of the earth: its rocks, layers, minerals and fossils.
Explore Dinosaurs · Ranger, Stop 2.2 (Ages 10–13)

geyserEnglish
A hot spring that erupts from time to time, when water deep underground is heated past boiling, flashes to steam and blasts the water above it into the air.
Explore Travel and Faraway Places · Expert, Stop 4.8 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 4.8 (Ages 10–13) · Explore Travel and Faraway Places, Stop 4.8 (Ages 7–9) · +2 more

Gila monsterEnglish
A heavy, beaded, black-and-pink or black-and-orange venomous lizard of the southwestern United States and northwestern Mexico (say “HEE-luh”).
Explore Animals · Ranger, Stop 3.10 (Ages 10–13) · Explore Animals, Stop 3.10 (Ages 7–9)

gillsEnglish
Body parts that let an animal breathe underwater.
Explore Animals, Stop 3.7 (Ages 7–9) · Explore Animals, Stop 4.1 (Ages 7–9) · Grade 1 Gardening & Animals, Lesson 4.2 (grade 1) · +3 more

GingerEnglish
A chestnut mare in the book who bites because she was badly treated.
Explore Horses and Ponies, Stop 4.2 (Ages 7–9)

girdleEnglish
A sash or belt worn around the waist. In verse 24 she makes girdles and delivers them to the merchant to sell.
Explore Hospitality and Home · Expert, Stop 4.1 (Ages 14+) · Explore Hospitality and Home · Ranger, Stop 4.1 (Ages 10–13) · Home Décor, Costume & Upholstery, Lesson 9.1 (grade 9–12)

girthEnglish
The strap that goes under the horse’s belly to hold an English saddle in place; on a Western saddle it is called a cinch.
Explore Horses and Ponies · Ranger, Stop 2.2 (Ages 10–13) · Explore Horses and Ponies, Stop 2.2 (Ages 7–9)

girth / cinchEnglish
The strap under the belly that holds the saddle on. English riders say girth; Western riders say cinch and fasten it with a long leather latigo.
Explore Horses and Ponies · Expert, Stop 2.2 (Ages 14+)

given toEnglish
In Romans 12:13, a translation of a Greek verb meaning “pursuing” or “chasing after.” Paul tells Christians to go looking for chances to be hospitable.
Explore Hospitality and Home · Expert, Stop 3.1 (Ages 14+)

gleanEnglish
To gather the grain left behind by the harvesters.
Explore Heroines of History and Faith, Stop 1.4 (Ages 7–9)

globeEnglish
A model of the earth on a sphere. It is the only kind of map that can keep shape, size, distance and direction all true at once.
Explore Travel and Faraway Places · Expert, Stop 1.1 (Ages 14+) · Explore Travel and Faraway Places · Ranger, Stop 1.1 (Ages 10–13) · Explore Travel and Faraway Places, Stop 1.1 (Ages 7–9) · +3 more

GLP-1English
Glucagon-like peptide-1: a human gut hormone released after meals that tells the pancreas to release insulin when blood sugar is high.
Explore Animals · Expert, Stop 3.10 (Ages 14+)

glycogen bodyEnglish
A pocket of energy-storing tissue in the hips of birds; a similar space in Stegosaurus hips was once mistaken for a “second brain.”
Explore Dinosaurs · Ranger, Stop 1.3 (Ages 10–13)

gnawEnglish
To bite and chew on something hard again and again.
Explore Animals, Stop 6.4 (Ages 7–9) · Grade 1 Gardening & Animals, Lesson 4.3 (grade 1) · Grade 1 Life Science: Animal Homes and Habits, Lesson 1.1 (grade 1)

GobiEnglish
A vast desert and dry grassland across southern Mongolia and northern China, cold in winter and hot in summer.
Explore Dinosaurs · Expert, Stop 2.8 (Ages 14+)

Gobi DesertEnglish
A huge, dry desert in Mongolia and northern China, famous for its red sandstone cliffs and fossils.
Explore Dinosaurs · Ranger, Stop 1.5 (Ages 10–13) · Explore Dinosaurs · Ranger, Stop 2.8 (Ages 10–13) · Explore Dinosaurs, Stop 1.5 (Ages 7–9) · +1 more

God-fearerEnglish
A Gentile who worshipped the God of Israel and attended Jewish prayers without fully becoming a Jew. Luke calls Lydia one “which worshipped God.”
Explore Hospitality and Home · Expert, Stop 4.7 (Ages 14+)

Godolphin ArabianEnglish
A real Arabian stallion of the 1700s, one of the three founders of the Thoroughbred breed.
Explore Horses and Ponies, Stop 4.6 (Ages 7–9)

godwitEnglish
A shorebird with long legs and a long, slightly upturned beak for probing in mud.
Explore Animals, Stop 6.7 (Ages 7–9)

Golden HornEnglish
The deep inlet on the north side of Constantinople, the city’s harbor, closed in time of siege by a great floating chain.
Explore Great Battles · Expert, Stop 2.7 (Ages 14+) · Explore Great Battles · Ranger, Stop 2.7 (Ages 10–13) · Explore Great Battles, Stop 2.7 (Ages 7–9) · +1 more