firefly

noun

fire·​fly ˈfī(-ə)r-ˌflī How to pronounce firefly (audio)
: any of various winged nocturnal beetles (especially family Lampyridae) that produce a bright soft intermittent light by oxidation of luciferin especially for courtship purposes

Illustration of firefly

Illustration of firefly

Examples of firefly in a Sentence

Recent Examples on the Web
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From the delicate dance of fireflies to the epic battles of stag beetles, this season pushes the boundaries of storytelling and scientific exploration. Tony Bradley, Forbes, 14 Jan. 2025 Jellyfish, fireflies, fungi, and more are all known to emit their very own glow. Laura Baisas, Popular Science, 9 Jan. 2025 Looking for love National Geographic/Stephen Alvarez A glowing firefly flying through the forest at night. Ars Technica, 14 Jan. 2025 Lucky for Southerners, our region is home to all kinds of one-of-a-kind natural experience—from catching the synchronous fireflies in Great Smoky Mountain National Park or Congaree National Park to kayaking to see bioluminescent plankton in Vero Beach, Florida. Tara Massouleh McCay, Southern Living, 26 Dec. 2024 See all Example Sentences for firefly 

Word History

First Known Use

1655, in the meaning defined above

Time Traveler
The first known use of firefly was in 1655

Dictionary Entries Near firefly

Cite this Entry

“Firefly.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/firefly. Accessed 30 Jan. 2025.

Kids Definition

firefly

noun
fire·​fly ˈfī(ə)r-ˌflī How to pronounce firefly (audio)
: any of numerous night-flying beetles that produce a bright soft flashing light for courtship purposes

More from Merriam-Webster on firefly

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