A mayfly is an insect which lives near water and only lives for a very short time as an adult.
mayfly in British English
(ˈmeɪˌflaɪ)
nounWord forms: plural-flies
1. Also called: dayfly
any insect of the order Ephemeroptera (or Ephemerida). The short-lived adults, found near water, have long tail appendages and large transparent wings; the larvae are aquatic
2. angling
an artificial fly resembling this
mayfly in American English
(ˈmeɪˌflaɪ)
nounWord forms: pluralˈmayˌflies
any of an order (Ephemeroptera) of delicate, soft-bodied insects with gauzy wings held vertically when at rest: in the adult stage, it lives only hours or a few days, but the aquatic larval stage may last for several years
Word origin
so named because thought to be most prevalent in May