The Collaborative International Dictionary of English v.0.48:

Bunko \Bun"ko\, v. t. [imp. & p. p. Bunkoed; p. pr. & vb. n.
   Bunkoing.]
   To swindle by a bunko game or scheme; to cheat or victimize
   in any similar way, as by a confidence game, passing a bad
   check, etc.
   [Webster 1913 Suppl.]

   Bunko steerer, a person employed as a decoy in bunko.
      [Slang, U.S.]
      [1913 Webster]