Ru·by n.; pl. Rubies
1. 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.
Note: ☞ Besides the true or Oriental ruby above defined, there are the balas ruby, or ruby spinel, a red variety of spinel, and the rock ruby, a red variety of garnet.
Of rubies, sapphires, and pearles white. --Chaucer.
2. The color of a ruby; carmine red; a red tint.
The natural ruby of your cheeks. --Shak.
3. That which has the color of the ruby, as red wine. Hence, a red blain or carbuncle.
4. Print. See Agate, n., 2. [Eng.]
5. Zool. Any species of South American humming birds of the genus Clytolaema. The males have a ruby-colored throat or breast.
Ruby of arsenic, Ruby of sulphur 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.
Ruby of zinc Min., zinc sulphide; the mineral zinc blende or sphalerite.
Ruby silver Min., red silver. See under Red.