Get the details behind our redesign


[mol-uh sk] /ˈmɒl əsk/
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.
Also, mollusc.
1775-85; < French mollusque < Neo-Latin Mollusca; see Mollusca
Related forms
molluskan, molluscan
[muh-luhs-kuh n] /məˈlʌs kən/ (Show IPA),
adjective, noun
mollusklike, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples for mollusk
  • It is about half crustaceans and the rest would be mollusk and other things.
  • Worse, it is hunted by crabs that try to crush the mollusk between strong claws.
  • Take the mollusk for instance, the only animal born with a shell.
  • Members of the mollusk family, nudibranchs abandoned their shells millions of years ago.
  • The quality of the water determines the edibility of the mollusk.
  • The sun feeds the algae, which in turn, nourishes the mollusk.
  • The mollusk instead coats the intruder with nacre, the secretion used to make its shell, forming a pearl.
  • The mollusk body, its tentacles writhing helplessly, drifts out of its protective house.
  • The center is working to restore fish and mollusk species.
British Dictionary definitions for mollusk


any invertebrate of the phylum Mollusca, having a soft unsegmented body and often a shell, secreted by a fold of skin (the mantle). The group includes the gastropods (snails, slugs, etc), bivalves (clams, mussels, etc), and cephalopods (cuttlefish, octopuses, etc)
Derived Forms
molluscan, (US) molluskan (mɒˈlʌskən) adjective, noun
mollusc-like, (US) mollusk-like, adjective
Word Origin
C18: via New Latin from Latin molluscus, from mollis soft
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for mollusk
1783, from Fr. mollusque, from Mod.L. Mollusca, order name, adopted by Linnæus 1758 from L. mollusca, neut. pl. of molluscus "thin-shelled," from mollis "soft," from PIE base *mel-/*mol-/*ml- "grind." Linnæus applied the word to a heterogeneous group of invertebrates, not originally including mollusks with shells; the modern scientific use is after a classification proposed 1790s by Fr. naturalist Georges Léopole Chrétien Frédéric Dagobert, Baron Cuvier (1769-1832).
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
mollusk in Science
mollusk or mollusc
Any of numerous invertebrate animals of the phylum Mollusca, usually living in water and often having a hard outer shell. They have a muscular foot, a well-developed circulatory and nervous system, and often complex eyes. Mollusks include gastropods (snails and shellfish), slugs, octopuses, squids, and the extinct ammonites. Mollusks appear in the fossil record in the early Cambrian Period, but it is not known from what group they evolved.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of The Day

Difficulty index for mollusk

Most English speakers likely know this word

Word Value for mollusk

Scrabble Words With Friends