crustacean

noun

crus·​ta·​cean ˌkrə-ˈstā-shən 

: any of a large class (Crustacea) of mostly aquatic mandibulate arthropods that have a chitinous or calcareous and chitinous exoskeleton, a pair of often much modified appendages on each segment, and two pairs of antennae and that include the lobsters, shrimp, crabs, wood lice, water fleas, and barnacles

crustacean adjective

Examples of crustacean in a Sentence

Recent Examples on the Web

Others are milk, eggs, sesame, fish, tree nuts, crustacean shellfish, soybeans and peanuts. —Thomas G. Moukawsher, Newsweek, 5 Feb. 2025

The new formal name, Cherax pulverulentus, means dusty crayfish in Latin, in homage to the crustacean’s dotted exoskeleton. —Margherita Bassi, Smithsonian Magazine, 15 Jan. 2025

In terms of sheer number of species, mollusks are second only to arthropods (the group that contains insects, spiders and crustaceans). —Kate Golembiewski, New York Times, 8 Jan. 2025

Water from ponds or other stagnant bodies of water can contain tiny crustaceans commonly known as water fleas, which in turn can be infected with Guinea worm larvae, according to the Centers for Disease Control and Prevention (CDC). —Mary Kekatos, ABC News, 31 Dec. 2024

Word History

First Known Use

1835, in the meaning defined above

Kids Definition

crustacean

noun

crus·​ta·​cean ˌkrəs-ˈtā-shən 

: any of a large class of mostly water-dwelling arthropods (as lobsters, shrimps, crabs, wood lice, water fleas, and barnacles) having an exoskeleton of chitin or chitin and a compound of calcium

crustacean adjective