/ Dictionary / Index G G-man: Meaning and Definition of Find definitions for: G-man Pronunciation: (jē'man"), [key] — pl. G-men. an agent for the FBI. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: g-man (Thesaurus) gm. G.M. and S. Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language