mayfly

noun

may·​fly ˈmā-ˌflī 

: any of an order (Ephemeroptera) of insects with an aquatic nymph and a short-lived, fragile adult lacking mouthparts and having membranous, heavily veined wings and two or three long, threadlike tails

Note: the wings of the mayfly are held vertically above the body when closed.

called also ephemerid

Illustration of mayfly

Examples of mayfly in a Sentence

Recent Examples on the Web

Each pseudo-scoop is as ephemeral as a mayfly. —David Remnick, New Yorker, 21 Mar. 2026

Here, the summer evening breeze ripples through the willows, and the terrace resounds with sounds of trout rising to catch the mayfly. —Condé Nast, Condé Nast Traveler, 12 Mar. 2026

Vitinha and Joao Neves flitted around like mayflies in love. —Jack Lang, New York Times, 26 Feb. 2026

Close-up Photographer of the Year announces 2025 winner A trippy image of a coral, a huge swarm of mayflies and a ravenous spider were among the winners of the Close-up Photographer of the Year award. —Alexandra Banner, CNN Money, 6 Feb. 2026

Word History

First Known Use

circa 1653, in the meaning defined above

Kids Definition

mayfly

noun

may·​fly -ˌflī 

: any of a group of insects that as adults live only a short time and have fragile wings