Synonyms and related words :
atomic, brittle, capricious, changeable, corpuscular, corruptible, deciduous, disappearing, dissolving, dying, embryonic, ephemeral, evaporating, fading, fickle, fleeting, flitting, fly-by-night, flying, fragile, frail, fugacious, fugitive, germinal, granular, impalpable, imperceptible, impermanent, impetuous, imponderable, impulsive, inappreciable, inconstant, indiscernible, infinitesimal, insubstantial, intangible, invisible, melting, microcosmic, microscopic, molecular, momentary, mortal, mutable, nondurable, nonpermanent, passing, perishable, short-lived, subatomic, temporal, temporary, tenuous, thin, transient, transitive, transitory, ultramicroscopic, undurable, unenduring, unseeable, unstable, vanishing, volatile