Breadcrumb Home > Dictionary > Index F firefly: Meaning and Definition of Find definitions for: fire•fly Pronunciation: (fīr'flī"), [key] — pl. -flies. any nocturnal beetle of the family Lampyridae, characterized by a soft body with a light-producing organ at the rear of the abdomen. Also calledCf. glowworm. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: firefly (Thesaurus) firefighter fire gilding TrendingHere are the facts and trivia that people are buzzing about. Biographies: Notable Jewish Religious Leaders Current Events This Week: September 2023 Hispanic Population and the 2010 U.S. Census 50 Spookiest Halloween Quotes Preamble of the United Nations Charter The Jewish Calendar ✖ Related Content Daily Word Quiz: panoply Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language