Pronunciation IPA (key): /krʌsˈteɪʃən/ Audio (US)(file) Noun Singular crustacean Plural crustaceans or crustacea The Simple English Wikipedia has an article on: Crustacean (countable) A crustacean is any arthropod within the subphylum Crustacea lobsters, crabs, and prawns are crustaceans. Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads