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

This action stirs up sediments and millimeter-scale organisms like brine shrimp and mayfly larvae, and generates miniature tornado-like whorls that spiral upward. —New Atlas, 15 May 2025

In the fast-moving air taxi and eVTOL market, things are jumping at a pace not seen since the dotcom bubble of the 1990s when flash new companies had the lifespan of mayflies with a chronic cough. —David Szondy, New Atlas, 5 Jan. 2025

Keep the rig small; mayfly larvae are rarely longer than an inch. —Alex Robinson, Outdoor Life, 13 June 2024

Starting in May and running through September, mayflies emerge all across North America. —Shaye Baker, Field & Stream, 6 June 2024

Word History

First Known Use

circa 1653, in the meaning defined above

Rhymes for mayfly

• safely

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