n. [ L. rubia madder, fr. rubeus red. ] (Chem.) One of several color-producing glycosides found in madder root. [ 1913 Webster ]
a. (Chem.) pertaining to, or derived from, rubian; specifically, designating an acid called also
n. [ Cf. LL. rubinus, It. rubino. See Ruby. ] A ruby. [ Obs. ] Spenser. [ 1913 Webster ]