| actin |
any of a group of contractile proteins, including proteins involved in muscle contraction, cell motility, and maintenance of cellular shape. |
| actinide |
any of the chemical elements of the actinide series. |
| actinogen |
any of the radioactive chemical elements. |
| actinomycin |
any of several antibiotics derived from soil bacteria that work against certain other bacteria and fungi. |
| adamant |
unlikely to change in response to any request or argument; firmly decided or fixed; unyielding. [2/3 definitions] |
| adder2 |
any of various similar poisonous or harmless snakes. [1/2 definitions] |
| adder's-tongue |
any of various ferns with a single sporeless leaflike frond and a slender spore-bearing spike or stalk that suggests a snake's tongue. [1/2 definitions] |
| adenovirus |
any of a group of viruses that causes disease of the upper respiratory tract. |
| admiral |
any of a family of brightly colored, medium to large-sized butterflies, found worldwide. [1/2 definitions] |
| Adonis |
(often l.c.) any young man who is extremely handsome. [1/2 definitions] |
| Adventist |
an adherent of any of several Christian denominations that believe in the imminent second coming of Jesus Christ. |
| aflatoxin |
any of a group of toxic compounds produced by certain molds, esp. those in the genus Aspergillus. Consumption of food contaminated with these molds can cause liver disease and cancer. |
| African violet |
any of several related tropical plants, very popular as houseplants, that have fuzzy dark green leaves and bear violet, pink, or white flowers. |
| afternoons |
in or during any, every, or a usual afternoon. |
| agaric |
any of numerous related fungi with gills on the underside of a cap; mushroom. |
| agave |
any of the tropical American plants, such as the century plant, that are related to the amaryllis and have tall, branched clusters of flowers and leaves with spiny edges. |
| age |
any time in life that has certain characteristics or involves certain rights and duties. [1/11 definitions] |
| ageratum |
any of various low-growing, cultivated American plants of the aster family, with violet-blue or white flowers. |
| aggression |
any offensive action or actions against others. [1/3 definitions] |
| agouti |
any of several related nocturnal, burrowing rodents found in the tropics of the Western Hemisphere that are about the size of a rabbit but have short ears and grizzled fur. |
| agrimony |
any of various related plants of the rose family that have compound feathery leaves and bear long clusters of small yellow flowers on spiky stalks, and a prickly fruit. [2 definitions] |