/gray/, adj., grayer, grayest, n., v.adj.1. of a color between white and black; having a neutral hue.2. dark, dismal, or gloomy: gray skies.3. dull, dreary, or monotonous.4. having gray hair; gray-headed.5. pertaining to old age; mature.6. Informal. pertaining to, involving, or composed of older persons: gray households.7. old or ancient.8. indeterminate and intermediate in character: The tax audit concentrated on deductions in the gray area between purely personal and purely business expenses.n.9. any achromatic color; any color with zero chroma, intermediate between white and black.10. something of this color.11. gray material or clothing: to dress in gray.12. an unbleached and undyed condition.13. (often cap.) a member of the Confederate army in the American Civil War or the army itself. Cf. blue (def. 5).14. a horse of a gray color.15. a horse that appears white but is not an albino.v.t., v.i.16. to make or become gray.Also, grey.[bef. 900; ME; OE graeg; c. G grau]gray2/gray/, n. Physics.the SI unit of absorbed dose, equal to the amount of ionizing radiation absorbed when the energy imparted to matter is 1 J/kg. Abbr.: Gy Cf. rad.[1975; named in honor of Louis Harold Gray (1905-65), English radiobiologist]
* * *(as used in expressions)Gray AsaGray ThomasOtis Harrison GrayAnne Gray Harvey
* * *▪ physicsunit of absorbed dose of ionizing radiation, defined in the 1980s by the International Commission on Radiation Units and Measurements. One gray is equal approximately to the absorbed dose delivered when the energy per unit mass imparted to matter by ionizing radiation is one joule per kilogram. As a unit of measure, the gray is coherent with the units of measure in the International System of Units (SI). The gray replaced the rad, which was not coherent with the SI system. One gray equals 100 rads.
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