DictionaryshellfishShelled aquatic animal
noun

shellfish

SHEL-fish/ˈʃelfɪʃ/

An aquatic invertebrate with a shell, often eaten as seafood.

The crab and mussel are shellfish protected by hard outer coverings.

A living crab beside a slightly open mussel in shallow coastal water, with their protective shells and aquatic setting clearly visible.
Etymology

Shell combines with fish in its older, broader sense of any aquatic animal. The name therefore describes a water-dwelling animal with a shell, rather than requiring it to be a fish in the narrower modern sense.

In context

NutritionFacts.org50:34
So is this neurotoxin present in Florida seafood? Yes, in both freshwater fish and shellfish – oysters and bass, etc., and out into the bay.
Food as Medicine: Preventing and Treating the Most Common Diseases with Diet

More examples

  • The restaurant serves fresh shellfish with lemon and butter.
  • Crabs are shellfish with hard outer coverings and jointed legs.
  • She checks local warnings before gathering shellfish along the shore.

Forms

shellfish · shellfishes

Similar words

crustacean
Specifically an animal with a jointed outer skeleton, like a crab.
mollusk
A soft-bodied invertebrate; some lack shells or live on land.