Nassa \Nas"sa\, n.; pl. E. {Nassas}, L. {Nass[AE]}. [From L. nassa a kind of basket, in allusion to the reticulation of some species.] (Zo["o]l.) Any species of marine gastropods, of the genera {Nassa}, {Tritia}, and other allied genera of the family {Nassid[ae]}; a dog whelk. See Illust. under {Gastropoda}. -- {nas"soid}, a.