[conch] n, pl conchs or conches [ME, fr. L concha mussel, mussel shell, fr. Gk konche; akin to Skt sankha conch shell] (15c) 1: any of various large spiral-shelled marine gastropod mollusks (as of the genus Strombus); also: its shell used esp. for cameos
2. often cap: a native or resident of the Florida Keys
3: concha
2.