The Collaborative International Dictionary of English v.0.48:

Bravo \Bra"vo\, n.; pl. Bravoes. [I. See Brave, a.]
   A daring villain; a bandit; one who sets law at defiance; a
   professional assassin or murderer.
   [1913 Webster]

         Safe from detection, seize the unwary prey.
         And stab, like bravoes, all who come this way.
                                                  --Churchill.
   [1913 Webster]