shell·fish 
/ˈʃɛlˌfɪʃ/ noun
plural shellfish /ˈʃɛlˌfɪʃ/ noun : an animal (such as a crab or an oyster) that has a hard outer shell and that lives in water [count] ▪ lobsters, crabs, and other shellfish [noncount] ▪ a serving of shellfish — see color picture
