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[fahyuh r-flahy] /ˈfaɪərˌflaɪ/
noun, plural fireflies.
any nocturnal beetle of the family Lampyridae, characterized by a soft body with a light-producing organ at the rear of the abdomen.
Also called glowfly, lightning bug.
Compare glowworm.
Origin of firefly
First recorded in 1650-60; fire + fly2 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
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British Dictionary definitions for firefly


noun (pl) -flies
any nocturnal beetle of the family Lampyridae, common in warm and tropical regions, having luminescent abdominal organs See 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
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Word Origin and History for firefly

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

Online Etymology Dictionary, © 2010 Douglas Harper
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