noun Abbr. Gy
The SI unit for the energy absorbed from ionizing radiation, equal to one joule per kilogram.
Origin of gray After Louis Harold Gray (1905-1965), British radiobiologist
(comparative grayer, superlative grayest) (spelled "grey" in the UK and the Commonwealth)
- Having a color somewhere between white and black, as the ash of an ember.
- Dreary, gloomy.
- Having an indistinct, disputed or uncertain quality.
- Relating to older people.
- the gray dollar, i.e. the purchasing power of the elderly
A mnemonic for remembering which spelling is used where: grey is the English spelling, while gray is the American spelling. However, grey is also found in American English.
(third-person singular simple present grays, present participle graying, simple past and past participle grayed) (spelled "grey" in the UK and the Commonwealth)
- To become gray.
- My hair is beginning to gray.
- To cause to become gray.
- (demography, slang) To turn progressively older, in the context of the population of a geographic region.
- the graying of America
(plural grays) (spelled "grey" in the UK and the Commonwealth)
- An achromatic colour intermediate between black and white.
- (chiefly US, ufology) an extraterrestrial creature with grayish skin, bulbous black eyes, and an enlarged head.
- (two-up) A penny with a tail on both sides, used for cheating.
From Old English grǣġ, from Proto-Germanic *grēwaz (compare Dutch grauw, German grau, Old Norse grár), from Pre-Germanic *ǵrēwo, from Proto-Indo-European *ǵʰer (“to shine, to glow”) (compare Latin rāvus (“grey”), Old Church Slavonic зьрѭ (zĭrjǫ, “to see, to glance”), Russian зреть (zretʹ, “to watch, to look at”) (archaic), Lithuanian žeriù (“to shine”)).
- In the International System of Units, the derived unit of absorbed dose of radiation (radiation absorbed by a patient); one joule of energy absorbed per kilogram of the patient's mass. Symbol: Gy
Origin See also: grey
Named after Louis Harold Gray.