| arm wrestling |
a contest in which each of two opponents places either the right or the left elbow on a table with the forearm vertical, clasps the opponent's hand, and tries to force the opponent's hand back until it touches the table; Indian wrestling. |
| arpeggio |
the playing of each note in a musical chord rapidly, one after the other rather than simultaneously. [1/2 definitions] |
| arsenic |
a poisonous chemical element that has thirty-three protons in each nucleus and occurs in brittle, grayish white crystalline masses or in yellow or black allotropes. (symbol: As) [1/2 definitions] |
| assembly line |
a way of putting together a product in a factory. The product moves along a line of people, and each person adds a part until the product is finished. |
| astatine |
a highly radioactive chemical element of the halogen group that has eighty-five protons in each nucleus. (symbol: At) |
| astraddle |
having one leg on each side; astride. |
| astride |
over or upon and with a leg on each side of. [2 definitions] |
| astrology |
the study of the positions of the heavenly bodies in relation to each other with the aim of predicting their influence on human affairs. |
| asynchronous |
in computing, having each operation start after the preceding operation is complete. [1/2 definitions] |
| at cross purposes |
so as to misunderstand or act in a way that frustrates each other's purposes. |
| at-large election |
an election in which every voter can vote for candidates to fill any and all vacant positions in a representative body. Unlike a single-member election, in which people can vote only for candidates who represent their particular legislative district, at-large elections allow every person to vote on each vacant position within a governing body. |
| auf Wiedersehen |
(German) until we see each other again; good-bye for now (used at parting). |
| au revoir |
(French) until we see each other again; good-bye for now. |
| backgammon |
a board game in which each of two opponents throws dice and tries to move several pieces clockwise around and eventually off the board. |
| back up |
of traffic, to become so slow that vehicles form long lines behind each other with little space between each vehicle. [1/8 definitions] |
| bacteria |
microscopic organisms that often play a role in the decay of living things, the process of fermentation, and sometimes in causing disease. Bacteria are each made up of only one cell, but different kinds of bacteria can take different shapes. These organisms live in all parts of the earth including oceans, deserts, glaciers, hot springs, and in the bodies of most living things. While some kinds of bacteria are dangerous, most kinds are useful because they help in the digestion of food, in the making of soil, in the creation of medicines, and in many other natural processes. |
| bacterium |
singular form of "bacteria." Bacteria are tiny living things made up of one cell each. Bacteria live in most living things and in all parts of the earth. Most bacteria are useful to people, but some are harmful because they can cause disease. |
| barbell |
a bar with weights attached at each end used for exercising and building muscle. Barbells are usually made of metal, and the weights can be changed to make the bar heavier or lighter. |
| barium |
a chemical element of the alkaline-earth group that has fifty-seven protons in each nucleus and that is usu. found in compounds such as salts. (symbol: Ba) [1/2 definitions] |
| barouche |
a four-wheeled carriage with a folding top, two opposing seats for two people each inside, and a driver's seat outside in front. |
| barrow1 |
a flat frame used for carrying a load. A barrow has two handles at each end or handles at one end and a wheel at the other; wheelbarrow. |