gray

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of or relating to an achromatic color of any lightness between the extremes of black and white.
• adjective Dull or dark.
• adjective Lacking in cheer; gloomy.
• adjective Having gray hair; hoary.
• adjective Old or venerable.
• adjective Intermediate in character or position, as with regard to a subjective matter.
• noun An achromatic color of any lightness between the extremes of black and white.
• noun An object or animal of the color gray.
• noun A member of the Confederate Army in the Civil War.
• noun The Confederate Army.
• intransitive verb To make gray.
• intransitive verb To become gray.
• intransitive verb To become old; age.
• intransitive verb To include a large or increasing proportion of older people.
• noun The SI unit for the energy absorbed from ionizing radiation, equal to one joule per kilogram.

from The Century Dictionary.

• To cause to become gray; change to a gray color.
• To depolish, as glass.
• In photography, to give a mezzotint effect by covering the negative during the printing with a glass slightly ground or depolished on one side. Pictures thus treated are sometimes called Berlin portraits.
• noun Unbleached cotton fabric; a piece of cotton or worsted cloth, in the natural color of the raw material, as it comes from the loom, before it is dyed or finished.
• noun Same as methylene gray.
• noun A water-color consisting of carbon-black, lake, and indigo.
• Of a color between white and black, having little or no positive color, and only moderate luminosity; of the color of black hair which has begun to turn white, as seen at some distance.
• Having gray hairs; gray-headed.
• Old; mature: as, gray experience.
• noun A gray color or tint; a color having little or no distinctive hue (chroma) and only moderate luminosity.
• noun An animal of a gray color.
• noun A gray horse.
• noun The gray duck, or gadwall.
• noun The California gray whale; the grayback.
• noun A kind of salmon, Salmo ferox.
• noun Twilight: as, the gray of the morning, or of the evening.
• noun plural A Scottish regiment of cavalry forming the second regiment of dragoons in the British army: so called from the color of their horses. Also Scots Grays.

from the GNU version of the Collaborative International Dictionary of English.

• noun A gray color; any mixture of white and black; also, a neutral or whitish tint.
• noun An animal or thing of gray color, as a horse, a badger, or a kind of salmon.
• noun (U. S. History) the Confederate army or a soldier in the confederate army.
• noun 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.
• adjective 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.
• adjective Gray-haired; gray-headed; of a gray color; hoary.
• adjective Old; mature.
• adjective gloomy; dismal.
• adjective (Min.) stibnite.
• adjective (Zoöl.) the chickara.
• adjective (Min.) smaltite.
• adjective (Min.) tetrahedrite.
• adjective (Zoöl.) the gadwall; also applied to the female mallard.
• adjective (Zoöl.) the peregrine falcon.