(n.) A reckless person without regard of consequence\; a wild ruffian.

Cain Judas apache assassin assassinator badman bandit betrayer bloodletter bloodshedder bravo bucko bully bullyboy burker butcher button man cannibal convict criminal crook cutthroat deceiver desperate criminal devil double-dealer eradicator executioner exterminator felon fugitive gallows bird gangster gaolbird garroter gorilla gun gunman gunsel hatchet man head-hunter hell-raiser hellcat hit man homicidal maniac homicide jailbird killer lawbreaker mad dog man-eater man-killer manslayer massacrer matador mobster murderer outlaw pesticide poison poisoner public enemy quisling racketeer rough rowdy ruffian scofflaw slaughterer slayer strangler swindler thief thug torpedo traitor trigger man two-timer