Synonyms and related words :
brittle, capricious, changeable, corruptible, deciduous, dying, ephemeral, evanescent, fading, fickle, fleeting, flitting, fly-by-night, flying, fragile, frail, fugacious, fugitive, impermanent, impetuous, impulsive, inconstant, insubstantial, momentary, mortal, mutable, nondurable, nonpermanent, passing, perishable, short-term, temporal, temporary, transient, transitive, transitory, undurable, unenduring, unstable, volatile