A fish with true fins, especially used to distinguish ordinary fish from shellfish or other aquatic creatures.
Compound of 'fin' (Old English 'finn') and 'fish' (Old English 'fisc'). The term became standardized in biological and commercial contexts in the 19th-20th centuries to clarify what type of aquatic animal was being discussed, distinguishing from mollusks and crustaceans.
Finfish might seem redundant—isn't all fish finned?—but the term actually exists because in commercial fishing, legally 'fish' can mean almost anything aquatic, creating confusion between finned fish and shellfish that are processed differently. The specificity shows how language adapts to solve real-world problems in industry.
Complete word intelligence in one call. Free tier — 50 lookups/day.