Source : Webster's Revised Unabridged Dictionary (1913)

Sea trout \Sea" trout`\ (Zo["o]l.)
   (a) Any one of several species of true trouts which descend
       rivers and enter the sea after spawning, as the European
       bull trout and salmon trout, and the eastern American
       spotted trout.
   (b) The common squeteague, and the spotted squeteague.
   (c) A California fish of the family {Chirid[ae]}, especially
       {Hexagrammus decagrammus}; -- called also {spotted rock
       trout}. See {Rock trout}, under {Rock}.
   (d) A California sci[ae]noid fish ({Cynoscion nobilis}); --
       called also {white sea bass}.

Source : WordNet®

sea trout
     n 1: flesh of marine trout that migrate from salt to fresh water
          [syn: {salmon trout}]
     2: any of several sciaenid fishes of North American coastal
        waters
     3: silvery marine variety of brown trout that migrates to fresh
        water to spawn