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

Illustration of firefly

Examples of firefly in a Sentence

Recent Examples on the Web

The lives of the two children in the story, aged fourteen and four, are portrayed as being as fleeting as the fireflies, and the story is an unsentimental and unflinching account with moments of both tenderness and heartlessness. —Ginny Tapley Takemori september 4, Literary Hub, 4 Sep. 2025

The views up high are incomparable at night, when lights in the surrounding hills twinkle like fireflies. —Sheri Castle, Southern Living, 31 Aug. 2025

Its primary food source is the winter firefly (Diaphanes lampyroides), which attracts mates with a continuous, non-flashing light. —Mrigakshi Dixit, Interesting Engineering, 29 Aug. 2025

Toyama is known for firefly squid, white shrimp, yellowfin tuna and pressed trout sushi. —Mark Zeigler, San Diego Union-Tribune, 29 Aug. 2025

Word History

First Known Use

1655, in the meaning defined above

Rhymes for firefly

• abscissae
• alibi
• alkali
• alumni
• amoebae
• amplify
• annuli
• beautify
• brachii
• butterfly
• calculi
• certify

Kids 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