Illustration of mayfly
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
Example Sentences
Recent Examples on the Web The mayfly hatch that put a little bit of a hiccup in the walleye catches around Western Lake Erie is winding down. 
D'arcy Egan, cleveland, 7 July 2022 Not to mention component and frame standards that have the life expectancy of a mayfly. Josh Patterson, Outside Online, 18 May 2020 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Significant drops have been found in mayfly populations in the American Midwest, butterfly numbers in the Sierra Nevadas, and caterpillar diversity in northern Costa Rica. Elizabeth Kolbert, The New Yorker, 25 Oct. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 See More
D'arcy Egan, cleveland, 7 July 2022 Not to mention component and frame standards that have the life expectancy of a mayfly. Josh Patterson, Outside Online, 18 May 2020 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Significant drops have been found in mayfly populations in the American Midwest, butterfly numbers in the Sierra Nevadas, and caterpillar diversity in northern Costa Rica. Elizabeth Kolbert, The New Yorker, 25 Oct. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 Some would sip the mouse like a tiny mayfly; others would leap completely out of the water, grabbing the fly on the way down. Chris Santella, Anchorage Daily News, 18 Sep. 2021 See More Word History
First Known Use
circa 1653, in the meaning defined above