/ Dictionary / Index F firebug: Meaning and Definition of Find definitions for: fire•bug Pronunciation: (fīr'bug"), [key] — n. Informal. arsonist; incendiary; pyromaniac. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: firebug (Thesaurus) fire brigade firebush Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language