steelhead vs. trout

noun

plural steelheads, (especially collectively) steelhead.
  1. a silvery rainbow trout that migrates to the sea before returning to fresh water to spawn.


noun

plural (especially collectively) trout, (especially referring to two or more kinds or species) trouts.
  1. any of several game fishes of the genus Salmo, related to the salmon. Compare brown trout, cutthroat trout, rainbow trout.
  2. any of various game fishes of the salmon family of the genus Salvelinus. Compare brook trout ( def 1 ), char 2, Dolly Varden ( def 2 ), lake trout.
  3. any of several unrelated fishes, as a bass, Micropterus salmoides, a drum of the genus Cynoscion, or a greenling of the genus Hexagrammos.