n. [ named after Louis Harold Gray, English radiobiologist. ] the SI unit of absorbed dosage of ionizing radiation, equal to an absorbed energy of 1 joule per kilogram of irradiated material; -- abbreviated Gy. This unit is 100 times the commonly used unit, the rad. [ PJC ]

a. [ Compar. Grayer superl. Grayest. ] [ OE. gray, grey, AS. gr&aemacr_;g, grēg; akin to D. graauw, OHG. grāo, G. grau, Dan. graa, Sw. grå, Icel. grār. ] [ Written also grey. ] 1. any color of neutral hue between white and black; white mixed with black, as the color of pepper and salt, or of ashes, or of hair whitened by age; sometimes, a dark mixed color; as, the soft gray eye of a dove. [ 1913 Webster ]

These gray and dun colors may be also produced by mixing whites and blacks. Sir I. Newton. [ 1913 Webster ]

2. Gray-haired; gray-headed; of a gray color; hoary. [ 1913 Webster ]

3. Old; mature; as, gray experience. Ames. [ 1913 Webster ]

4. gloomy; dismal. [ PJC ]

Gray antimony (Min.), stibnite. --
Gray buck (Zool.), the chickara. --
Gray cobalt (Min.), smaltite. --
Gray copper (Min.), tetrahedrite. --
Gray duck (Zool.), the gadwall; also applied to the female mallard. --
Gray falcon (Zool.) the peregrine falcon. --
Gray Friar. See Franciscan, and Friar. --
Gray hen (Zool.), the female of the blackcock or black grouse. See Heath grouse. --
Gray mill or
Gray millet (Bot.), a name of several plants of the genus Lithospermum; gromwell. --
Gray mullet (Zool.) any one of the numerous species of the genus Mugil, or family Mugilidæ, found both in the Old World and America; as the European species (Mugilidæ capito, and Mugilidæ auratus), the American striped mullet (Mugilidæ albula), and the white or silver mullet (Mugilidæ Braziliensis). See Mullet. --
Gray owl (Zool.), the European tawny or brown owl (Syrnium aluco). The great gray owl (Ulula cinerea) inhabits arctic America. --
Gray parrot (Zool.), an African parrot (Psittacus erithacus), very commonly domesticated, and noted for its aptness in learning to talk. Also called jako. --
Gray pike. (Zool.) See Sauger. --
Gray snapper (Zool.), a Florida fish; the sea lawyer. See Snapper. --
Gray snipe (Zool.), the dowitcher in winter plumage. --
Gray whale (Zool.), a rather large and swift whale of the northern Pacific (Eschrichtius robustus, formerly Rhachianectes glaucus), having short jaws and no dorsal fin. It grows to a length of 50 feet (someimes 60 feet). It was formerly taken in large numbers in the bays of California, and is now rare; -- called also grayback, devilfish, and hardhead. It lives up to 50 or 60 years and adults weigh from 20 to 40 tons. [ 1913 Webster ]

n. 1. A gray color; any mixture of white and black; also, a neutral or whitish tint. [ 1913 Webster ]

2. An animal or thing of gray color, as a horse, a badger, or a kind of salmon. [ 1913 Webster ]

Woe worth the chase, woe worth the day.
That coats thy life, my gallant gray. Sir W. Scott. [ 1913 Webster ]

3. (U. S. History) the Confederate army or a soldier in the confederate army; as, a battle between the blue and the gray. [ PJC ]

n. (Zool.) (a) The California gray whale. (b) The redbreasted sandpiper or knot. (c) The dowitcher. (d) The body louse. [ 1913 Webster ]

n. An old man. Shak. [ 1913 Webster ]

n. (Zool.) The trumpet fly. Milton. [ 1913 Webster ]

adj. showing characteristics of age, especially having gray or white hair.
Syn. -- gray, grey, grey-haired, grey-headed, hoar, hoary. [ WordNet 1.5 ]

n. (Zool.) See Greyhound. [ 1913 Webster ]

a. Somewhat gray. [ 1913 Webster ]

n. (Zool.) The common wild gray goose (Anser anser) of Europe, believed to be the wild form of the domestic goose. See Illust. of Goose. [ 1913 Webster ]