Tartarean \Tar*ta"re*an\, Tartareous \Tar*ta"re*ous\, a. [L. tartareus: cf. F. tartar['e]en.] Of or pertaining to Tartarus; hellish. Tartareous \Tar*ta"re*ous\, a. [Cf. 1st {Tartarous}.] 1. Consisting of tartar; of the nature of tartar. 2. (Bot.) Having the surface rough and crumbling; as, many lichens are tartareous.