ephemeral \ih-FEM-er-ul\, adjective:
1. Beginning and ending in a day; existing only, or no longer than, a day; as, an ephemeral flower.
2. Short-lived; existing or continuing for a short time only.
Ephemeral derives from Greek ephemeros, from epi, upon + hemera, day.
Synonyms: passing, short-lived, transient, transitory, fugacious