[ru.by] n, pl rubies [ME, fr. MF rubis, rubi, alter. of robin, fr. ML rubinus, fr. L rubeus reddish; akin to L ruber red--more at red] (14c) 1 a: a precious stone that is a red corundum b: something (as a watch bearing) made of ruby
2. a: the dark red color of the ruby b: something resembling a ruby in color
[2]ruby adj (1508): of the color ruby