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

Founded in 2009 by third-generation lobsterman Luke Holden, the lobster roll chain noted for its signature crustacean rolls. —Brock Keeling, Oc Register, 13 Aug. 2025

The heatwave disrupted ocean circulation patterns, which impacted the number of cold, nutrient-rich waters that support the small crustaceans, according to the National Oceanic and Atmospheric Administration (NOAA). —Michelle Del Rey, USA Today, 11 Aug. 2025

Along with the worm, rock-scraping mollusks and filter-feeding crustaceans were also discovered. —John Leos, AZCentral.com, 1 Aug. 2025

Named for the distinctive black markings on the tips of their dorsal, pelvic, and tail fins, blacktip sharks primarily eat small fish, squid, and crustaceans, using quick bursts of speed to chase down prey. —Melissa Cristina Márquez, Forbes.com, 1 June 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