[fahyuh r-flahy]

noun, plural fire·flies.

any nocturnal beetle of the family Lampyridae, characterized by a soft body with a light-producing organ at the rear of the abdomen.

Compare glowworm.

Origin of firefly

First recorded in 1650–60; fire + fly2
Also called glowfly, lightning bug. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for firefly

fireworm, glowworm, lampyrid, noctiluca

Examples from the Web for firefly

Contemporary Examples of firefly

Historical Examples of firefly

British Dictionary definitions for firefly


noun plural -flies

any nocturnal beetle of the family Lampyridae, common in warm and tropical regions, having luminescent abdominal organsSee also glow-worm
any tropical American click beetle of the genus Pyrophorus, esp P. noctiluca, that have luminescent thoracic organs
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for firefly

1650s, from fire (n.) + fly (n.).

Online Etymology Dictionary, © 2010 Douglas Harper