female proper name, shortened form of Molly, itself familiar for Mary. Used from c.1600 for "prostitute;" meaning "companion of a thief" is first recorded 1823. A general word for "woman" in old underworld slang, for instance Moll-buzzer "pickpocket who specializes in women;" Moll-tooler "female pick-pocket." U.S. sense of "a gangster's girlfriend" is from 1923.