Illustration of firefly
firefly
noun
fire·fly
ˈfī(-ə)r-ˌflī 
: any of various winged nocturnal beetles (especially family Lampyridae) that produce a bright soft intermittent light by oxidation of luciferin especially for courtship purposes
Examples of firefly in a Sentence
Recent Examples on the Web
Yet there’s a warmth to every song that’s watching fireflies twinkle against a summer sunset.
—
David Glickman, Pitchfork, 13 Feb. 2026
Standing in the backyard and watching fireflies in the summertime is very relaxing.
—Tim Johnson, Chicago Tribune, 3 Jan. 2026
Installations range from California poppies and a field of fireflies to a laser garden.
—Ut Community Press, San Diego Union-Tribune, 30 Dec. 2025
Alternatively, consider timing your trip for the firefly season, which begins in mid-March and runs for about a month.
—Lydia Mansel, Travel + Leisure, 20 Dec. 2025
See All Example Sentences for firefly
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David Glickman, Pitchfork, 13 Feb. 2026
Standing in the backyard and watching fireflies in the summertime is very relaxing.
—Tim Johnson, Chicago Tribune, 3 Jan. 2026
Installations range from California poppies and a field of fireflies to a laser garden.
—Ut Community Press, San Diego Union-Tribune, 30 Dec. 2025
Alternatively, consider timing your trip for the firefly season, which begins in mid-March and runs for about a month.
—Lydia Mansel, Travel + Leisure, 20 Dec. 2025
See All Example Sentences for firefly
Cite this Entry
“Firefly.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/firefly. Accessed 17 Feb. 2026.
Copy CitationKids Definition
firefly
noun
fire·fly
ˈfī(ə)r-ˌflī
: any of numerous night-flying beetles that produce a bright soft flashing light for courtship purposes
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