<p><strong>Noun:</strong></p><ul><li>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.</li></ul><p><strong>Adjective:</strong></p><ul><li>Belonging or pertaining to the crustaceans.</li></ul>