the.com/gangster

means A member of an organized criminal gang, especially one built around violence, racketeering, and a reputation that does a lot of the enforcing for you.

from Straightforward compound: 'gang' (a group traveling or working together, from Old Norse/Old English roots meaning 'a going' or 'journey') plus the agent suffix '-ster.' The word surfaces in American English in the late 1800s as cities grew fast and organized crews grew with them, and it exploded in the Prohibition era, when bootlegging turned small-time hoods into household names — and gave the word its lasting flavor of pinstripes, tommy guns, and operatic self-regard.