| bicycle |
a light vehicle with two wheels, one behind the other, a small seat, and handlebars for steering. Pedals make the wheels move. [1/2 definitions] |
| biennial |
lasting two years. [4/5 definitions] |
| bilingual |
able to speak two languages well. [2 definitions] |
| binary |
having two parts or components. [2 definitions] |
| binary system |
a numbering system with a base of two. In binary numbers, any number can be expressed by 1, 0, or a combination of these. The number five is written as "101" in the binary system. |
| biplane |
an early type of airplane with two sets of wings mounted one above the other. |
| bird |
an animal with two wings, two feet, and a body covered with feathers. Most birds can fly. Birds are warm-blooded animals with skeletons inside their bodies. Birds lay eggs with hard shells. Robins, eagles, chickens, and ostriches are a few of the many kinds of birds. |
| bisect |
to cut or split into two equal parts. [1/2 definitions] |
| bobsled |
a long racing sled with two separate sets of runners, a steering wheel, and brakes. [1/2 definitions] |
| book |
sheets of paper bound together between two covers. These pages can be blank or can have writing, printing, or pictures on them. [1/3 definitions] |
| border |
the line between two countries, states, or towns. [1/5 definitions] |
| both |
the two together; one and the other. [2/3 definitions] |
| bout |
a match or fight between two people in wrestling or boxing. [1/2 definitions] |
| bow2 |
a weapon used for shooting arrows. A bow is made of a curved strip of wood or other material with a cord stretched tight between the two ends. [2/4 definitions] |
| branch |
to separate into two or more paths, roads, or directions. [1/4 definitions] |
| breast |
either of the two glands on the human chest, usually bigger on women than on men. Babies get milk from female breasts. [1/2 definitions] |
| brig |
a sailing ship with two masts and square sails. [1/2 definitions] |
| brigantine |
a two-masted sailing vessel with square-rigged sails on the front mast and a fore-and-aft mainsail. |
| buckle |
a fastener, usually made of metal, that is used to join two ends of something. [2/6 definitions] |
| camel |
a large animal with long legs and a long neck. Camels are domesticated mammals; people use camels for riding and for carrying loads across deserts. Camels from the deserts of Central Asia have two humps. Camels from northern Africa and the Middle East have one hump. |
| cart |
a large wagon with two wheels pulled by animals and used to carry a heavy load. [1/4 definitions] |