mutable

likely to change frequently, suddenly, or unexpectedly a politician with very mutable positions on all the issues Synonyms capricious, changeable, changeful, flickery, fluctuating, fluid, inconsistent, inconstant, mercurial, fickle, skittish, temperamental, uncertain, unpredictable, unsettled, unstable, unsteady, variable, volatileRelated Words aimless, arbitrary, desultory, erratic, haphazard, hit-or-miss, irregular, random, scattered, slapdash, stray; ambivalent, hesitating, shaky, shilly-shally, shilly-shallying, vacillating, wavering; dicey, undependable, unreliable, untrustworthy; adaptable, mobile, protean, versatileNear Antonyms equable, even, uniform; abiding, durable, lasting, permanent, persistent; dependable, reliable, sure, tried, tried-and-true, true, trustworthy, trustyAntonyms certain, changeless, constant, immutable, invariable, predictable, settled, stable, stationary, steady, unchangeable, unchanging, unvarying