Synonyms and related words :
adrift, afloat, agitable, airy, alternating, amorphous, birdbrained, birdwitted, bouncy, brittle, bubbly, buoyant, capricious, changeable, changeful, charged, coquettish, corruptible, deciduous, desultory, deviable, dizzy, downy, dying, eccentric, edgy, effervescent, ephemeral, erratic, eruptive, ethereal, evanescent, evaporable, evaporative, expansive, explosive, faddish, fading, fast and loose, featherbrained, feathery, fickle, fitful, fleeting, flickering, flighty, flippant, flirtatious, flitting, fluctuating, fluffy, fly-by-night, flying, foamy, fragile, frail, freakish, frivolous, frothy, fugacious, fugitive, giddy, gossamery, hair-trigger, impermanent, impetuous, imponderous, impulsive, inconsistent, inconstant, indecisive, infirm, insubstantial, irregular, irresolute, irresponsible, leger, light, light as air, light-minded, lighter than vanity, lubricious, mazy, mercurial, momentary, moody, mortal, mousse, mutable, nondurable, nonpermanent, passing, perishable, protean, quicksilver, rambling, resilient, restless, roving, scatterbrained, sensitive, shallow, shallow-headed, shallow-minded, shallow-pated, shallow-witted, shapeless, shifting, shifty, short-lived, shuffling, skittery, skittish, souffle, spasmodic, spineless, startlish, superficial, temperamental, temporal, temporary, tense, ticklish, toying, transient, transitive, transitory, unaccountable, uncertain, uncontrolled, undependable, undisciplined, undurable, unenduring, unfixed, unheavy, unpredictable, unprofound, unreliable, unrestrained, unsettled, unstable, unstable as water, unstaid, unsteadfast, unsteady, vacillating, vagrant, vaporable, vaporescent, vaporizable, vaporizing, variable, versatile, vicissitudinary, vicissitudinous, volatilizable, wandering, wanton, wavering, wavery, wavy, wayward, weightless, whimsical, wishy-washy, yeasty