| acromegaly |
a chronic disease causing abnormal enlargement of the hands, feet, and parts of the face, usu. caused by a tumor of the pituitary gland. |
| acronym |
a type of abbreviation used as a word and pronounced as a word. An acronym is formed by combining the initial letters (or initial parts) of a string of words. The pronunciation of an acronym is based on the typical rules of pronouncing words in a language and is not made up of the sounds of the names of individual letters. The abbreviations "AIDS," "FICA," and "PIN" are acronyms, but the abbreviations "FBI," ATM," and "DVD" are not. |
| acrophobia |
an overwhelming fear of high places. |
| acropolis |
a fortified hill of an ancient Greek city. [2 definitions] |
| across |
from one side or end to the other of. [6 definitions] |
| across the board |
applying equally to all parts or members. |
| acrostic |
a sequence of written lines in which particular letters, usu. the first letter of every line, form an independent word or phrase. [2 definitions] |
| acrylic |
of or characteristic of the corrosive liquid acrylic acid. [2 definitions] |
| acrylic fiber |
any of a group of synthetic fibers that are made chiefly of acrylonitrile that has been formed into polymers. |
| acrylic resin |
any of a group of transparent synthetic resins that become pliable or set when heated and are used in acrylic fibers, plastics, and synthetic rubbers. |
| acrylonitrile |
a poisonous and carcinogenic liquid that is made into polymers for use as raw material in acrylic fibers. |
| act |
something done, esp. a specific instance; deed. [14 definitions] |
| actable |
capable of being acted, as a role or a play. |
| ACTH |
a hormone produced by the anterior pituitary that stimulates the cortex of the adrenal gland to produce cortisone and other hormones; adrenocorticotropic hormone. |
| actin |
any of a group of contractile proteins, including proteins involved in muscle contraction, cell motility, and maintenance of cellular shape. |
| acting |
appointed as a temporary substitute for someone absent from an office or position; serving temporarily. [5 definitions] |
| actinic |
of or pertaining to the chemical property of ultraviolet radiation and x-rays that produces photochemical effects. |
| actinic rays |
electromagnetic radiation, such as x-rays or ultraviolet light, that can produce an image on a photographic emulsion. |
| actinide |
any of the chemical elements of the actinide series. |
| actinide series |
the series of chemical elements, mostly synthetic and all radioactive, that have from eighty-nine to 103 protons per atom. |
| actinism |
the property of radiation that produces chemical activity. |