Prawns are edible shrimp-like crustaceans; in Britain the name is applied to any large shrimp, usually Leander serratus; in the United States the word prawn usually indicates a fresh-water, rather than salt-water, shrimp. The word in Middle English is prayne or prane, and no cognate forms are found in any other languages. It has been often connected to the Latin perna, a ham-shaped shellfish, but this is due to an old scholarly error which connected perna and parnocchie with prawne-fishes or shrimps. In fact, the Old Italian perna and pernocchia meant a shellfish which yielded nacre or mother-of-pearl.
Crustaceans
