Sometimes Disparaging. a man whose beard is gray; old man; sage.
A very senior pilot (1970s+ Airline)
noun 1. a small, bushy birch, Betula populifolia, of stony or sandy areas of the eastern U.S., having grayish-white bark and triangular leaves.
noun, Physics. 1. 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.