Mobster

Noun

 * 1) a member of a criminal gang

Thesaurus
Judas, bad person, bandit, betrayer, brigand, convict, criminal, crook, dacoit, deceiver, delinquent, desperado, desperate criminal, double-dealer, evildoer, felon, fugitive, gallows bird, gangster, gaolbird, hoodlum, jailbird, lawbreaker, malefactor, malevolent, malfeasant, malfeasor, misfeasor, mobsman, outlaw, public enemy, quisling, racketeer, scofflaw, sinner, swindler, thief, thug, traitor, transgressor, two-timer, villain, worker of ill, wrongdoer

Etymology
Derived from.