mollusk

noun

mol·​lusk ˈmä-ləsk 

variants or mollusc

: any of a large phylum (Mollusca) of invertebrate animals (such as snails, clams, or squids) with a soft unsegmented body usually enclosed in a calcareous shell

broadly : shellfish

molluscan adjective

or less commonly molluskan

mə-ˈlə-skən 

mä-

Examples of mollusk in a Sentence

Recent Examples on the Web

Pearls, on the other hand, are made by soft-bodied mollusks in reaction to an irritant that has entered their shell. —Caitlin Kennedy, Scientific American, 25 Apr. 2026

These massive mollusks may even have eaten large aquatic reptiles like mosasaurs and plesiosaurs, which were themselves believed to be among the main marine predators of the time. —Adam England, PEOPLE, 24 Apr. 2026

Buried within the stone was a tooth-bearing ribbon called a radula, a feature shared by all mollusks such as nautiluses and octopuses. —Samantha Agate, Miami Herald, 23 Apr. 2026

As omnivores, North American river otters eat fish, turtles, crabs, mollusks, birds, oysters, shellfish, crayfish, frogs, rodents and insects. —Hanna Wickes, Sacbee.com, 22 Apr. 2026

Word History

Etymology

French mollusque, from New Latin Mollusca, from Latin, neuter plural of molluscus thin-shelled (of a nut), from mollis

First Known Use

1783, in the meaning defined above

Rhymes for mollusk

• mollusc

Kids Definition

mollusk

noun

mol·​lusk

variants or mollusc

ˈmäl-əsk 

: any of a large phylum of invertebrate animals (as snails, clams, and octopuses) with a soft body lacking segments and usually enclosed in a shell containing calcium

molluscan adjective

also molluskan

mə-ˈləs-kən 

mä-

Medical Definition

mollusk

noun

mol·​lusk

variants or mollusc

ˈmäl-əsk 

: any invertebrate animal of the phylum Mollusca

molluscan adjective

also molluskan

mə-ˈles-kən, mä-