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

They are known to parasitize crustaceans and insects including praying mantids, beetles, crickets, and occasionally millipedes and centipedes, according to the study. —Lauren Liebhaber, Miami Herald, 6 Oct. 2025

According to a September Instagram post from the English train service, a passenger recently informed a conductor, named Mark Walsh, that there was a single crustacean in a first-class seat. —Moná Thomas, PEOPLE, 26 Sep. 2025

Not all transparent animals are gelatinous; the upper ocean is also full of transparent crustaceans of all kinds. —Literary Hub, 25 Sep. 2025

For now, at least, The Lost Correspondent can focus his reports on crustaceans, rather than conflict. —The Editors, JSTOR Daily, 19 Sep. 2025

Word History

First Known Use

1835, in the meaning defined above

Rhymes for crustacean

• ablation
• bination
• carnation
• cassation
• castration
• causation
• centration
• cessation
• cetacean
• chelation
• citation
• collation

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