Fleeting

a.

1.

Passing swiftly away; not durable; transient; transitory; as, the fleeting hours or moments.

Adj.

1.

fleeting - lasting for a markedly brief time; "a fleeting glance"; "fugitive hours"; "rapid momentaneous association of things that meet and pass"; "a momentary glimpse" Synonyms: fugitive, momentaneous, momentary

abrupt, blunt, brittle, brusque, capricious, changeable, compendious, corruptible, crusty, curt, deciduous, disappearing, dissolving, dying, ephemeral, evanescent, evaporating, fading, fickle, flitting, fly-by-night, flying, fragile, frail, fugacious, fugitive, gruff, impermanent, impetuous, impulsive, inconstant, insubstantial, laconic, melting, momentary, mortal, mutable, nondurable, nonpermanent, perishable, short, short and sweet, short-lived, snippety, snippy, succinct, temporal, temporary, terse, transient, transitive, transitory, undurable, unenduring, unstable, vanishing, volatile