ephemeral

Definitions:

Anything that is ephemeral.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
Continuing or existing one day only; short- lived.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (adjective) (adj.) (adjective)
Beginning and ending in a day; existing one day only; continuing for a short time only.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (adjective) (adj.) (adjective)
Lasting but a day; short- lived.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (adjective) (adj.) (adjective)
Existing only for a day; shortlived.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adjective) (adj.) (adjective)
Existing only for a day: daily: short- lived.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adjective) (adj.) (adjective)

Usage examples:

The greatest portion of your literature, at any given time, is ephemeral indeed, it has ever been so since the discovery of printing; and this portion it is which is most influential, consequently that by which most good or mischief is done.
- Colloquies on Society by Robert Southey
Her eyes met the Countess's, and the Countess, after resting on their surface with an ephemeral pause, murmured: 'I must not praise my brother, ' and smiled a smile which was meant to mean: 'I think with you, and thank you, and love you for admiring him.
- The Complete Project Gutenberg Works of George Meredith by George Meredith
These may all be ephemeral in their nature.
- The Complete Essays of C. D. Warner by Charles Dudley Warner