firefly
Americannoun
noun
-
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
Other Word Forms
Noun Inflected Forms
Etymology
Origin of firefly
Explanation
Fireflies are flying beetles that glow in the dark. If you gently catch a firefly between your palms, you can watch its light flicker on and off for a while, and then let it go. Depending on where you live, you may call fireflies "lightning bugs" or "glowworms." There are fewer of these light-emitting insects on the planet than there used to be, but you can still find places where they gather in groups at dusk, glowing and flickering like stars. Contrary to their name, fireflies aren't flies, but instead belong to a family of beetles with an amazing ability to produce a luminous light.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The Photinus carolinus species of firefly has just a few weeks every summer to flash their bioluminescent lights and mate.
From The Wall Street Journal ● Jun. 3, 2026
Chief among them is Photinus carolinus, also known as the Smokies synchronous firefly, which produces dazzlingly coordinated displays that rival even the most extravagant Christmas light installation.
From The Wall Street Journal ● Jun. 3, 2026
There was such a discussion about how a firefly flashes — How many seconds?
From Los Angeles Times ● Mar. 27, 2025
“It takes the light coming from the firefly and bends it and amplifies it so we can see it in glorious detail,” he told BBC News.
From BBC ● Dec. 11, 2024
A tiny firefly has landed on Autumn’s nose, shining golden light right onto her face.
From "Kwame Crashes the Underworld" by Craig Kofi Farmer
The trick is also shared by certain squid and jellyfish species, as well as insects such as fireflies and glow-worms.
From BBC ● Jun. 25, 2026
Some female fireflies, including those of the Smokies synchronous variety, stay on the ground while the males fly around.
From The Wall Street Journal ● Jun. 3, 2026
In a way, all animals make rhythms, whether in the form of fireflies flashing, birds chirping or even a tiger pacing back and forth.
From Salon ● Jun. 7, 2025
Reeve: This whole time, we’re watching Oliver and Claire travel to see these fireflies, and because that moment is actually quite quick, it had to land.
From Los Angeles Times ● Mar. 27, 2025
I broke his gaze, pretending to be distracted by fireflies.
From "Legendary Frybread Drive-In" by Cynthia Leitich Smith
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
