[kruh-stey-shuh n]


any chiefly aquatic arthropod of the class Crustacea, typically having the body covered with a hard shell or crust, including the lobsters, shrimps, crabs, barnacles, and wood lice.


belonging or pertaining to the crustaceans.

Origin of crustacean

1825–35; < New Latin Crustace(a) (neuter plural) hard-shelled ones (see crust, -acea) + -an Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for crustacean

Contemporary Examples of crustacean

Historical Examples of crustacean

  • “This is a magnificent specimen of the crustacean period,” he declared.


    Caroline Lockhart

  • This crustacean tube a thousand feet long solved the matter.

    James Watt

    Andrew Carnegie

  • Its punishment was simply that it was a Sacculina—that it was a Sacculina when it might have been a Crustacean.

  • Nature has willed that the Crustacean should not long remain an invalid.

    The Ocean World:

    Louis Figuier

  • Crabs and lobsters may be regarded as the chiefs or lords of the Crustacean tribes.

    The Ocean World:

    Louis Figuier

British Dictionary definitions for crustacean



any arthropod of the mainly aquatic class Crustacea, typically having a carapace hardened with lime and including the lobsters, crabs, shrimps, woodlice, barnacles, copepods, and water fleas

adjective Also: crustaceous

of, relating to, or belonging to the Crustacea

Word Origin for crustacean

C19: from New Latin crūstāceus hard-shelled, from Latin crūsta shell, crust
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for crustacean

1835, from Crustacea the class name. As an adjective, 1858 (earlier was crustaceous, 1640s).

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for crustacean



Any of various widespread arthropods of the class Crustacea that live mostly in water and have a hard shell, a segmented body, and jointed appendages. Crustaceans include crabs, lobsters, shrimp, barnacles, and copepods.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for crustacean



A class of arthropods with shells.


Crabs, lobsters, shrimp, and crayfish are crustaceans.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.