any of a family (Lobotidae) of percoid fishes that have large, trailing dorsal and anal fins; esp., a large food fish (Lobotes surinamensis) of warm W Atlantic waters
See tripletail in American Heritage Dictionary 4
(trĭpˈəl-tālˌ)
noun
Any of several chiefly marine percoid fishes of the family Lobotidae, especially Lobotes surinamensis, of warm waters of the western Atlantic, having prominent dorsal and anal fins that resemble extra tails.