aplysia

‖n. [ Gr. &unr_; a dirty sponge, fr. &unr_; unwashed; 'a priv. + &unr_; to wash. ] (Zool.) A genus of marine mollusks of the order Tectibranchiata; the sea hare. Some of the species when disturbed throw out a deep purple liquor, which colors the water to some distance. See Illust. in Appendix. [ 1913 Webster ]