firefly

noun fire·fly \ ˈfī(-ə)r-ˌflī \

Updated on: 12 Apr 2018

Definition of firefly

: any of various winged nocturnal beetles (especially family Lampyridae) that produce a bright soft intermittent light by oxidation of luciferin especially for courtship purposes

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Recent Examples of firefly from the Web

Trapped in its gravitational clutches, run-of-the-mill stars whip around this gargantuan black hole like fireflies in a hurricane.

— lee billings, Scientific American, "Astronomers Spy Swarms of Black Holes at Our Galaxy's Core," 4 Apr. 2018
Research suggests that the male fireflies that flash the longest may be considered ideal mates.

— jennifer billock, Smithsonian, "This Is the Best Place in North America to See Synchronous Fireflies," 3 Apr. 2018
Each white ball, glow stick glowing inside, was a firefly in action.

— monica drake, Longreads, "Doomed in Nashville," 5 Mar. 2018
This annual event showcases the synchronous fireflies (photinus carolinus), one of the few species in the world who coordinate their flash patterns, according to the National Park Service.

— katina beniaris, Country Living, "Thousands of Fireflies Will Light Up the Great Smoky Mountains This May," 27 Apr. 2017
At least seven firefly bills have been proposed since the 2016 legislative session.

— arika herron, Indianapolis Star, "Say's Firefly to become state insect after bill lights its way through the Indiana House," 27 Feb. 2018
This May, thousands of fireflies will deliver a mesmerizing display in the Great Smoky Mountains.

— katina beniaris, Country Living, "Thousands of Fireflies Will Light Up the Great Smoky Mountains This May," 27 Apr. 2017
Among the themes that light up like fireflies here and there are the nature of sin, the purpose of art, the low status of actors and the low status of humans in general.

— jesse green, New York Times, "Review: ‘The Amateurs’ Takes On God, Noah’s Ark and the Plague. For Laughs.," 27 Feb. 2018
Similar to the glow of a firefly, the bright blue flashes lighting up the ocean waves are the biochemical reaction of small, algae-like organisms known as dinoflagellates.

— Sunset, "This Rare Marine Phenomenon Is Making the Pacific Glow," 22 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'firefly.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of firefly

First Known Use of firefly

1655

FIREFLY Defined for English Language Learners

firefly

noun

Definition of firefly for English Language Learners

: a small flying insect that produces a soft light

FIREFLY Defined for Kids

firefly

noun fire·fly \ ˈfīr-ˌflī \

Definition of firefly for Students

plural fireflies

: a small beetle producing a soft light

Learn More about firefly

See words that rhyme with firefly Spanish Central: Translation of firefly Nglish: Translation of firefly for Spanish speakers Britannica English: Translation of firefly for Arabic speakers Britannica.com: Encyclopedia article about firefly

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firefly

Definition of firefly

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firefly

Definition of firefly for English Language Learners

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firefly

Definition of firefly for Students

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