释义 |
gam·ma I. \ˈgamə\ noun (-s) Etymology: Middle English, from Late Latin, from Greek, of Semitic origin; akin to Hebrew gīmel gimel 1. : the third letter of the Greek alphabet — symbol Γ or γ; see alphabet table 2. a. : the degree of contrast of a developed photographic image b. : the slope of the straight-line portion of the characteristic curve of a photographic material or process c. : a measure of the faithfulness with which the brightness variation in a television scene is reproduced in the displayed picture 3. a. : a unit of magnetic intensity equal to 0.00001 oersted b. : a gamma-ray quantum c. : one millionth of a gram : microgram II. adjective or γ- \“\ 1. : of or relating to one of three or more closely related chemical substances < γ-yohimbine > — used somewhat arbitrarily to specify ordinal relationship or to specify a particular physical form, especially an allotropic modification (as in γ-iron), or an isomeric or stereoisomeric form (as in γ-benzene hexachloride) 2. : third in position in the structure of an organic molecule from a particular group or atom or having a structure characterized by such a position < γ-hydroxy acids > < γ-lactones > 3. : third in order of brightness — used of a star in a constellation 4. of streptococci : producing no hemolysis on blood agar plates |