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

By creating a kind of prehistoric food web, the researchers placed animals like sea bream (which eat mussels and crustaceans) at the bottom, followed by smaller sharks and extinct toothed whales the size of modern dolphins. —Melissa Cristina Márquez, Forbes.com, 11 June 2025

Kevin Dietsch/Getty Images There are nine major allergens, including soybeans, wheat, sesame, milk, eggs, fish, crustacean shellfish, tree nuts and peanuts. —Marni Rose McFall, MSNBC Newsweek, 10 June 2025

These two parasite species have historically infected people in Southeast Asia who eat raw fish, crustaceans or vegetables that carry the parasite larvae. —Karen Garcia, Los Angeles Times, 4 June 2025

The researchers found that sea bream, a fish that feeds on mussels and crustaceans, was at the bottom of their reconstructed chain, followed by smaller sharks from the Carcharhinus genus, up to 9.8 feet (3 meters) in length, and extinct toothed whales comparable in size to modern dolphins. —Jacopo Prisco, CNN Money, 27 May 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