/krʌˈsteɪʃn ||; krʌsˈteʃən/noun [C] (technical术语) any creature with a soft body in several sections and covered with a hard outer shell. Crustaceans usually live in water. 甲壳纲动物: Crabs, lobsters, shrimps and prawns are crustaceans. 螃蟹、龙虾、小虾及明虾都是甲壳纲动物。