fluid

1 capable of moving like a liquid warm the jam until it is fluid, then spread it over the cake Synonyms flowing, fluent, liquid Related Words circumfluent, circumfluous; diluted, thin, watery, weak; semiliquid, semisolid Near Antonyms clotted, coagulated, gelatinous, gelled, jelled, jellied, thick; gluey, glutinous, gooey, gummy, viscous Antonyms hard, nonliquid, solid

2 capable of being readily changed the script is still fluid at this point, so be prepared for last-minute rewrites Synonyms adaptable, adjustable, alterable, changeable, elastic, flexible, malleable, modifiable, pliable, variableRelated Words changing, fluctuating, inconstant, labile, unstable, unsteady, varying, versatileNear Antonyms constant, stable, steady, unchanging, uniform, unvaryingAntonyms established, fixed, immutable, inelastic, inflexible, invariable, nonmalleable, ramrod, set, unadaptable, unalterable, unbudgeable, unchangeable

3 involving minimal difficulty or effort the dance looked smooth and fluid, though backstage we could see the dancer gasping for breath and sweating from the effort Synonyms cheap, downhill, effortless, facile, fluent, easy, hands-down, light, painless, ready, royal, simple, smooth, snap, softRelated Words idiotproof, mindless, quick, straightforward, unchallenging, uncomplicated; apparent, clear, clear-cut, distinct, evident, manifest, obvious, open-and-shut, palpable, patent, perspicuous, plain, transparent, unambiguous, unequivocal, unmistakableNear Antonyms burdensome, exhausting, onerous, oppressive, painful, stressful, taxing, troublesome; abstruse, complex, complicated, intricate, involved, knotty, problematic (also problematical), reconditeAntonyms arduous, demanding, difficult, exacting, formidable, grueling (or gruelling), hard, herculean, killer, labored, laborious, murderous, rough, severe, stiff, strenuous, toilful, toilsome, tough

4 likely to change frequently, suddenly, or unexpectedly his arrival plans are fluid, so expect him anytime Synonyms capricious, changeable, changeful, flickery, fluctuating, fickle, inconsistent, inconstant, mercurial, mutable, 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