/ Dictionary / Index M mollusk: Meaning and Definition of Find definitions for: mol•lusk Pronunciation: (mol'usk), [key] — n. any invertebrate of the phylum Mollusca, typically having a calcareous shell of one, two, or more pieces that wholly or partly enclose the soft, unsegmented body, including the chitons, snails, bivalves, squids, and octopuses. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mollusk (Thesaurus) molluscum Mollweide projection Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language