may·​fly | \ ˈmā-ˌflī How to pronounce mayfly (audio) \

Definition of mayfly

: 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

Illustration of mayfly

Examples of mayfly in a Sentence

Recent Examples on the Web Gone are the small leeches and magnum mayfly larvae that captivate the bluegills’ attention during the summer months. Outdoor Life, "5 Bluegill Facts That Will Help You Catch More Fish," 27 Jan. 2020 For instance, mayflies, which only live and breed for a day, can be confused by light bouncing off asphalt and lay their eggs in the street instead of a lake or stream. Jason Daley, Smithsonian, "The Devastating Role of Light Pollution in the ‘Insect Apocalypse’," 26 Nov. 2019 Ever the river has risen and brought us the flood, the mayfly floating on the water. Joan Acocella, The New Yorker, "How to Read “Gilgamesh”," 7 Oct. 2019 Biologists have noticed a distinct diet shift, with perch foraging on invertebrates such as spiny water fleas and midge and mayfly larvae instead of emerald shiner minnows and other small fish. D'arcy Egan,, "Lake Erie walleye fishing ‘Golden Era’ officially returns with record catches, big hatches," 13 Sep. 2019 Perch have also been suspending well off the lake bottom to feed on invertebrates such as spiny water fleas, midge larvae and mayfly larvae, rather than minnows. D'arcy Egan, cleveland, "Lake Erie walleye hitting; yellow perch are hit-and-miss: Fishing Report for Sept. 20," 20 Sep. 2019 Stepanian and Wainwright are now using their radar analysis to track the spectacular emergence of mayflies in the Upper Midwest every summer. Carolyn Kormann, The New Yorker, "The Changing Climate Inside the World’s Largest Bat Colony," 6 Aug. 2019 Many of the sport anglers and fishing guides are trolling the wide waters, which were littered with the skeletons of millions of hatching mayflies. D'arcy Egan,, "Lake Erie walleye head to deeper waters, but still plentiful: June 5 Fishing Report," 5 July 2019 Little of this comes through in the film, which is about the mayfly moment and three people at its center. Ty Burr,, "‘Leto’ revisits Soviet socialist rock ’n’ roll," 31 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mayfly.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of mayfly

circa 1653, in the meaning defined above

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Time Traveler for mayfly

Time Traveler

The first known use of mayfly was circa 1653

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Last Updated

3 Feb 2020

Cite this Entry

“Mayfly.” Dictionary, Merriam-Webster, Accessed 23 Feb. 2020.

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How to pronounce mayfly (audio)

English Language Learners Definition of mayfly

: a small flying insect that lives for only a short time

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Rhyming Dictionary: Words that rhyme with mayfly

Spanish Central: Translation of mayfly

Nglish: Translation of mayfly for Spanish Speakers

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