mollusc n. + Add to list UK //mˈɒlʌsk// mol·lusc SynonymsEtymology Synonyms molluskshellfishOriginLATmolluscus→LA-NEWMollusca→ENmollusc Borrowed from French mollusque, from New Latin Mollusca (phylum name), from Latin molluscus (“thin-shelled”), from mollis (“soft”).