| Noun | 1. | neritid - operculate seasnail of coastal waters with a short spiral shell seasnail - any of several creeping marine gastropods with a spirally coiled shell: whelks; tritons; moon shells; neritids family Neritidae, Neritidae - neritids nerita - a neritid gastropod having a short smooth or spirally ridged shell with thick usually toothed outer lip and toothed operculum bleeding tooth, Nerita peloronta - gastropod having reddish toothlike projections around the shell opening; of the Caribbean area neritina - ornately marked and brightly colored snails of brackish waters |