n. pl. shellfish or shell·fish·es
1. Any of various edible aquatic invertebrate animals having a shell, especially mollusks such as clams and oysters, and crustaceans such as lobsters, crabs, and shrimp.
2. An edible mollusk, in contrast to a crustacean: regulations concerning fish, crustaceans, and shellfish.
3. The edible flesh of such animals.
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.