a. [ Litho- + Gr. &unr_; to eat. ] (Zool.) (a) Eating or swallowing stones or gravel, as the ostrich. (b) Eating or destroying stone; -- applied to various animals which make burrows in stone, as many bivalve mollusks, certain sponges, annelids, and sea urchins. See Lithodomus. [ 1913 Webster ]