Dayfly

noun

1. A May-fly: a popular name of the neuropterous insects of the family Ephemeridæ: so called because, however long they may live in the larval state, in their perfect form they exist only from a few hours to a few days, taking no food, but only propagating and then dying. See Ephemeridæ.
2. A neuropterous insect of the genus Ephemera and related genera, of many species, and inhabiting fresh water in the larval state; the ephemeral fly; -- so called because it commonly lives but one day in the winged or adult state. See Ephemeral fly, under ephemeral.
3. A mayfly.
4. slender insect with delicate membranous wings having an aquatic larval stage and terrestrial adult stage usually lasting less than two days