Real Dictionary

Gray in American English
Asa1810-88; U.S. botanist

gray in American English 1
an achromatic color made by mixing or blending black and white
of a color that is a mixture or blend of black and white
to make or become gray
adjective: of a color between white and black; having a neutral hue
noun: any achromatic color; any color with zero chroma, intermediate between white and black

gray in American English 2
the basic unit of an absorbed dose of radiation in the SI system, equal to the absorption of one joule of energy per kilogram of material (100 rads)
noun: the SI unit of absorbed dose, equal to the amount of ionizing radiation absorbed when the energy imparted to matter is 1 J/kg

Gray in British English
noun: Simon ( James Holiday). 1936–2008, British writer: his plays include Butley (1971), The Common Pursuit (1988), Life Support (1997), and Japes (2001)

gray in British English 2
noun: the derived SI unit of absorbed ionizing radiation dose or kerma equivalent to an absorption per unit mass of one joule per kilogram of irradiated material. 1 gray is equivalent to 100 rads