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

Sea sponges also provide a habitat for worms, crustaceans, and juvenile fish. — Laura Baisas, Popular Science, 30 July 2026

Fishing boats as far north as Alaska caught unusual species, and fewer tiny crustaceans known as copepods were found off the Oregon coast. — Dinah Voyles Pulver, USA Today, 30 July 2026

Ferreira explained that their captors usually feed them white bread instead of the algae and tiny crustaceans their bodies require. — ABC News, 29 July 2026

The Karches went out hunting for spiny lobster early in the morning on the first day of the two-day miniseason for the clawless crustaceans. — David Goodhue, Miami Herald, 29 July 2026

Word History

First Known Use

1835, in the meaning defined above

Rhymes for crustacean

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

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