shellfish
/ˈʃelfɪʃ/noun
(复同单)
1- an aquatic shelled mollusc (e.g. an oyster or cockle) or a crustacean (e.g. a crab or shrimp), especially one that is edible有壳水生动物。
1.1
- mass noun such molluscs or crustaceans as food贝壳（或甲壳）类食物。