ephemera Meaning, Definition & Usage

  1. noun something transitory; lasting a day
  2. noun anything short-lived, as an insect that lives only for a day in its winged form
    ephemeron; ephemeral.

WordNet

E*phem"e*ra noun
Etymology
NL., fr. Gr. a day fly, fr. daily, lasting but a day; over + day.
Definitions
  1. (Med.) A fever of one day's continuance only.
  2. (Zoöl.) A genus of insects including the day flies, or ephemeral flies. See Ephemeral fly, under Ephemeral.

Webster 1913