Definition of "ephemeral" in English

adjective

1. Lasting for a short period of time.

   • 1821-1822, Vicesimus Knox, Remarks on the tendency of certain Clauses in a Bill now pending in Parliament to degrade Grammar Schools Esteem, lasting esteem, the esteem of good men, like himself, will be his reward, when the gale of ephemeral popularity shall have gradually subsided.

2. (biology) Existing for only one day, as with some flowers, insects, and diseases.

3. (geology, of a body of water) Usually dry, but filling with water for brief periods during and after precipitation.

   • The graben constitutes a depositional basin and a topographic low, underlain by Cretaceous shales, in which volcanic debris accumulated in ephemeral lakes and streams in Oligocene and early Miocene time.

noun

1. Something which lasts for a short period of time.