Ephemeral /(?)/

E·phem·er·al

Ephemeral

a.
  1. Beginning and ending in a day; existing only, or no longer than, a day; diurnal; as, an ephemeral flower.
  2. Short-lived; existing or continuing for a short time only.
    Sentences not of ephemeral, but of eternal, efficacy.
    — Sir J. Stephen.

Phrases & Compounds
Ephemeral fly
one of a group of neuropterous insects, belonging to the genus Ephemera and many allied genera, which live in the adult or winged state only for a short time. The larvæ are aquatic; -- called also day fly and May fly.

Ephemeral

n.
  1. Anything lasting but a day, or a brief time; an ephemeral plant, insect, etc.