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 To follow Trump was to be a mayfly and a pine tree at once. Helen Lewis, The Atlantic, "The Anti-Trump Hangover Is Here," 10 Nov. 2020 Most of the mayfly action in mid to late fall involves that group of species collectively known as blue-winged olives. Field & Stream, "The 10 Best Trout Flies for Late Fall Fishing," 13 Oct. 2020 The company believes long stretches of higher temperatures in North Texas and a holding lot’s proximity to a lake led to an unusual increase in mayfly populations. Dom Difurio, Dallas News, "Mayflies taint launch of GM’s most profitable new line of vehicles in Arlington," 2 Sep. 2020 Anglers dislike them because the Lake Erie fishing can go into a bit of a funk when the mayfly hatching reaches a peak. cleveland, "Mayflies are in full flight over Lake Erie, which helps those seeking walleye and perch: Northeast Ohio fishing report for Thursday, June 25," 25 June 2020 With walleye of all sizes grazing on hatching mayflies, the diminutive mayfly rigs are now coming into play. cleveland, "Mayflies are in full flight over Lake Erie, which helps those seeking walleye and perch: Northeast Ohio fishing report for Thursday, June 25," 25 June 2020 Catch giant browns and rainbows on these tiny bugs At first, the whole scenario sounds implausible: A nationwide mayfly hatch that starts in July and peaks in August. John Merwin, Field & Stream, "How to Fish for Trout During the Summer Trico Hatch," 23 June 2020 The riverbottom is home to huge numbers of scuds and larvae from midges, caddis, stones, and mayflies. John B. Snow, Outdoor Life, "The Godfather of Montana’s Bighorn River," 28 Apr. 2020 With all due respect, that coalition had the life span of a mayfly. Kevin Baker, Harper's Magazine, "Losing My Religion," 30 Mar. 2020

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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Cite this Entry

“Mayfly.” Dictionary, Merriam-Webster, Accessed 7 Mar. 2021.

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English Language Learners Definition of mayfly

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

More from Merriam-Webster on mayfly

Nglish: Translation of mayfly for Spanish Speakers

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