noun

a member of a gang of violent criminals.

gangsters threatened to kill him if he did not cooperate in the theft

hoodlum,racketeer,bandit,robber,ruffian,thug,tough,desperado,outlaw,villain,lawbreaker,criminal,gunman,murderer,assassin,terrorist,gang member,member of a criminal gang,member of the Mafia,Mafioso,yakuza,mobster,crook,hitman,hatchet man,heavy,hood,brigand