| arrowhead |
the wedge-shaped barb on the striking end of an arrow. [3 definitions] |
| arroyo |
a steep ditch or gully, usu. dry, carved in a plain or desert by drainage of heavy rainfall. |
| arsenal |
a building used for the storage or manufacture of weapons, munitions, and other military equipment; armory. [3 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) [2 definitions] |
| arson |
the illegal act of burning buildings, another's or one's own, for malicious purposes or to claim insurance money. |
| art |
a fine skill that allows one to create a thing of excellence, beauty, or deep meaning that has resulted from natural ability, practice, or study. [4 definitions] |
| artefact |
variant of artifact. |
| artery |
a vessel that carries blood away from the heart. (Cf. vein.) [2 definitions] |
| arthritis |
a disease of the joints in which they become painfully inflamed. |
| arthropod |
a class of invertebrates with hard, segmented bodies and jointed legs, including insects, spiders, crustaceans, and myriapods. |
| artichoke |
a tall thistlelike plant whose flower head, composed of thick, leaflike scales, is cooked and eaten. [2 definitions] |
| article |
a single item or thing, esp. one of a class or group. [4 definitions] |
| articulate |
spoken in clear and distinct words or syllables, or having a tendency to speak clearly and distinctly. [10 definitions] |
| articulated lorry |
(chiefly British) a very large truck, consisting of a cab and freight-hauling trailer, that carries goods over long distances; tractor-trailer; semi. |
| artifact |
any object made by human beings, esp. one of an earlier era. [2 definitions] |
| artificial |
created by human beings. [3 definitions] |
| artificial intelligence |
research in and development of computer programs that imitate human thought processes such as reasoning or decision-making. |
| artificial respiration |
the resumption or continuation of a person's breathing, as by forcing air into and out of the person's lungs. |
| artillery |
mounted large-caliber weapons, such as cannons or rocket launchers, used in land warfare and manned by a crew. [3 definitions] |
| artisan |
a person skilled in making things, esp. with the hands; craftsperson. |
| artist |
a person who is skilled at painting, sculpting, music, writing, or the like. [3 definitions] |