ruby

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

• noun A deep red, translucent variety of the mineral corundum, highly valued as a precious stone.
• noun Something, such as a watch bearing, that is made from a ruby.
• noun A dark or deep red to deep purplish red.
• adjective Of the color ruby.

from The Century Dictionary.

• noun In 1887, M. Frémy, with the aid of his preparateur, M. Verneuil, undertook new experiments on the crystallization of alumina, and had the satisfaction of obtaining very beautiful artificial rubies. Now M. Verneuil, today professor at the Museum, has discovered the method of producing the ruby artificially by melting a mixture of alumina and oxide of chrome at a constant temperature of several thousands of degrees, and in layers superposed from the outside to the inside, in order to prevent the production of cracks in the crystalline mass. This eminent chemist has succeeded in creating a magnificent ruby, weighing about 2,500 grams, and having a commercial value of about 3,000 francs. …
• noun The deepest red topaz which owes its color to heating, to the right degree, of the yellow Brazilian topaz. Further heating turns it pink, and still continued heating renders it colorless. See topaz.
• noun The clear rich-red variety of corundum. (See corundum.)
• noun A pure or somewhat crimson red color.
• noun Something resembling a ruby; a blain; a blotch; a carbuncle.
• noun In heraldry, the tincture red or gules, when blazoning is done by means of precious stones. See blazon, n., 2.
• noun In printing, a type smaller than nonpareil and larger than pearl, about the size of American agate, or 5½ points in the new system of sizes.
• noun In horology: Any variety of ruby used as jewels in watchmaking, as in the finest watches. Hence—
• noun The jewel of the roller of the balance-staff of a watch, irrespective of the material of which it is made. Compare jewel, n., 4.
• noun In ornithology: The red bird of paradise, Paradisea rubra or sanguinea.
• noun The ruby hummer, Clytolæma rubineus of Brazil, and some related humming-birds with ruby gorget.
• Of a color resembling that of the ruby; of a rich red color inclining toward crimson.
• To make red.

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

• transitive verb rare To make red; to redden.
• noun (Min.) A precious stone of a carmine red color, sometimes verging to violet, or intermediate between carmine and hyacinth red. It is a red crystallized variety of corundum.
• noun The color of a ruby; carmine red; a red tint.
• noun That which has the color of the ruby, as red wine. Hence, a red blain or carbuncle.
• noun (Print.), engraving See Agate, n., 2.
• noun (Zoöl.) Any species of South American humming birds of the genus Clytolæma. The males have a ruby-colored throat or breast.
• noun (Chem.) a glassy substance of a red color and a variable composition, but always consisting chiefly of the disulphide of arsenic; -- called also ruby sulphur.
• noun (Min.) zinc sulphide; the mineral zinc blende or sphalerite.
• noun (Min.) red silver. See under Red.
• adjective Ruby-colored; red.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A clear, deep, red variety of corundum, valued as a precious stone.
• noun A deep red colour.
• noun typography, UK Type having a height of 5.5 points.
• noun A ruby hummer, a South American hummingbird, Clytolaema rubricauda.
• noun A red bird-of-paradise, Paradisaea rubra.
• adjective Of a deep red colour (having any of numerous bright colours reminiscent of the colour of blood or cherries or tomatoes).
• verb transitive, poetic To make red; to redden.
• noun A pronunciation guide written above or beside Chinese or Japanese characters.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a deep and vivid red color
• noun a transparent deep red variety of corundum; used as a gemstone and in lasers
• noun a transparent piece of ruby that has been cut and polished and is valued as a precious gem
• adjective of a color at the end of the color spectrum (next to orange); resembling the color of blood or cherries or tomatoes or rubies