any body that emits radiation at each wavelength in a constant ratio less than unity to that emitted by a black body at the same temperature.
noun, Photography. 1. a card of controlled reflectance held near a subject to approximate middle tones and used as a target for an exposure meter.
- Gray cataract
gray cataract n. A cataract of gray color usually occurring in senile, mature, or cortical cataracts.
noun 1. See under . [kat-burd] /ˈkætˌbɜrd/ noun 1. any of several American or Australian birds having catlike cries, especially Dumetella carolinensis (gray catbird) of North America. /ˈkætˌbɜːd/ noun 1. any of several North American songbirds of the family Mimidae (mockingbirds), esp Dumetella carolinensis, whose call resembles the mewing of a cat 2. any of […]
- Gray-cheeked thrush
[grey-cheekt] /ˈgreɪˌtʃikt/ noun 1. a North American thrush, Catharus minimus, having olive upper parts and grayish cheeks.