| 4WD |
abbreviation of "four-wheel drive," a car that drives by means of all four wheels rather than the rear wheels only, or the drive system of such, in which both front and rear wheel axles are turned by the drive shaft. |
| a2 |
used to introduce one particular thing or person of a group or kind, but one which is not considered known to the listener. [1/3 definitions] |
| abalone |
a large edible marine snail, the shell of which is lined with mother-of-pearl. |
| abandon |
a state in which emotions or impulses control one completely. [1/6 definitions] |
| abomasum |
the fourth stomach chamber of cud-chewing mammals such as cows, in which food is digested. |
| ABO system |
a classification system for the inherited antigens found on the surface of human red blood cells, which determine compatibility for blood transfusions. |
| above |
that which is above. [1/9 definitions] |
| Abscam |
in the United States, an FBI investigation in 1978-80, as a result of which several members of Congress were indicted for taking bribes from FBI agents posing as Arab businessmen. |
| absolute monarchy |
an authoritarian governing system in which a hereditary ruler holds complete power until death. |
| absolute temperature |
temperature measured on a scale in which zero equals the lowest temperature that can be obtained physically. |
| acacia |
any of several tropical trees of the mimosa family, some of which produce the commercially useful gum arabic. [1/2 definitions] |
| acetabulum |
the cup-shaped socket of the hipbone into which the top of the thighbone fits. [1/2 definitions] |
| acetal |
any of a class of chemicals in which aldehydes are compounded with alcohol. [1/2 definitions] |
| acetaminophen |
a drug used to relieve pain and reduce fever but which does not significantly reduce inflammation. |
| achromatic |
able to give an image in which colors are reproduced with little or no distortion. [1/3 definitions] |
| Acremonium |
the genus of fungi, formerly known as Cephalosporium, from which the antibiotic cephalosporin was originally isolated. Several species may cause disease in humans, esp. pneumonia. |
| acrostic |
a sequence of written lines in which particular letters, usu. the first letter of every line, form an independent word or phrase. [1/2 definitions] |
| Acts of the Apostles |
the fifth book of the New Testament of the Christian Bible, believed to have been written by Luke, which describes the work of Jesus Christ as it was carried on after his death by his apostles. |
| adaptation |
in biology, that which results from the process of adaptation. [1/4 definitions] |
| adobe |
the clay of which such material is made. [1/3 definitions] |
| aeropause |
the level at which the earth's atmosphere becomes too thin for airplanes to fly. |