transient

Definitions:

Passing; not abiding.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (adjective) (adj.) (adjective)
Transientness, transience.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)
TRANSIENTNESS.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
Passing: of short duration: not lasting: mementary.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adjective) (adj.) (adjective)
TRANSIENTLY.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adverb) (adv.) (adverb)
Fleeting; brief; passing; temporary, as lodgers.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adjective) (adj.) (adjective)
Transience, transiency.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)

Usage examples:

Constance's eye followed him as far as the door, where their glances met for an instant in the transient gaze which expresses the tenderness of people who feel more than they kiss.
- The Old Wives' Tale by Arnold Bennett
Like to this fleeting glory, carmined deep, The season of thy power is transient Do good, whilst yet thou canst- 'before thine eyes Close in thy last, forgetting, silent sleep.
- The Dales of Arcady by Dorothy Una Ratcliffe
To- morrow he would realise that shouting and the clapping of hands are as transient as the wind in the trees; but to- night they were, after all, something well worth winning.
- The Mayor of Warwick by Herbert M. Hopkins