Unstable

• POS: Adjective
• HYPHEN: un=sta=ble

CIDE DICTIONARY

Unstable, a. [Cf. Instable.].

 Not stable; not firm, fixed, or constant; subject to change or overthrow.  [1913 Webster]

Unstable equilibrium. See Stable equilibrium, under Stable.

OXFORD DICTIONARY

Unstable, adj. (unstabler, unstablest)
1 not stable.
2 changeable.
3 showing a tendency to sudden mental or emotional changes.

Idiom

unstable equilibrium a state in which a body when disturbed tends to move farther from equilibrium.

Derivative

unstableness n. unstably adv.

THESAURUS

Unstable

adrift, afloat, alternating, ambiguous, amorphous, borderline, brittle, buoyant, canted, capricious, changeable, changeful, changing, choppy, corruptible, crumbling, dangerous, deciduous, decrepit, desultory, deviable, deviating, deviative, deviatory, dickey, different, disintegrating, disorderly, divaricate, divergent, diversified, diversiform, dizzy, doubtful, dubious, dying, eccentric, effervescent, elastic, ephemeral, erose, erratic, evanescent, fading, fast and loose, fickle, fitful, fleeting, flickering, flighty, flitting, fluctuant, fluctuating, fluid, fly-by-night, flying, fragile, frail, freakish, fugacious, fugitive, giddy, hazardous, heeling, ill-balanced, impermanent, impetuous, impulsive, inconsistent, inconstant, indecisive, indefinite, infirm, insecure, insubstantial, irregular, irresolute, irresponsible, jagged, jerky, leaning, listing, lopsided, lubricious, mazy, mercurial, mobile, momentary, moody, mortal, motley, moving, mutable, nonconformist, nondurable, nonpermanent, nonstandard, nonuniform, off-balance, overbalanced, passing, perilous, perishable, pluralistic, poor, poorish, precarious, protean, provisional, ragged, rambling, resilient, restless, risky, rocky, rootless, rotten, rotten at, rough, roving, scatterbrained, shaky, shapeless, short-lived, shuffling, slippery, spasmodic, spineless, sporadic, suspect, temperamental, temporal, temporary, tentative, tergiversating, ticklish, top-heavy, tottery, transient, transitive, transitory, treacherous, tricky, unaccountable, unbalanced, uncertain, uncontrolled, undecided, undependable, undisciplined, undurable, unenduring, unequable, unequal, uneven, unfaithworthy, unfirm, unfixed, unhealthy, unorthodox, unpredictable, unreliable, unrestrained, unsafe, unsettled, unsolid, unsound, unstable as water, unstaid, unsteadfast, unsteady, unsturdy, unsubstantial, unsure, unsystematic, untrustworthy, ununiform, vacillating, vagrant, variable, variegated, variform, various, varying, vicissitudinary, vicissitudinous, volatile, wandering, wanton, wavering, wavery, wavy, wayward, weak, whimsical, wishy-washy, wobbly

ROGET THESAURUS

Unstable

Danger

N danger, peril, insecurity, jeopardy, risk, hazard, venture, precariousness, slipperiness, instability, defenselessness, exposure, vulnerability, vulnerable point, heel of Achilles, forlorn hope, leap in the dark, road to ruin, faciles descensus Averni, hairbreadth escape, cause for alarm, source of danger, rock ahead, breakers ahead, storm brewing, clouds in the horizon, clouds gathering, warning, alarm, apprehension, in danger, endangered, fraught with danger, dangerous, hazardous, perilous, parlous, periculous, unsafe, unprotected &c (safe, protect), insecure, untrustworthy, built upon, sand, on a sandy basis, wildcat, defenseless, fenceless, guardless, harborless, unshielded, vulnerable, expugnable, exposed, open to, aux abois, at bay, on the wrong side of the wall, on a lee shore, on the rocks, at stake, in question, precarious, critical, ticklish, slippery, slippy, hanging by a thread, with a halter round one's neck, between the hammer and the anvil, between Scylla and Charybdis, between a rock and a hard place, between the devil and the deep blue sea, between two fires, on the edge of a precipice, on the brink of a precipice, on the verge of a precipice, on the edge of a volcano, in the lion's den, on slippery ground, under fire, not out of the wood, unwarned, unadmonished, unadvised, unprepared, off one's guard, tottering, unstable, unsteady, shaky, top-heavy, tumbledown, ramshackle, crumbling, waterlogged, helpless, guideless, in a bad way, reduced to the last extremity, at the last extremity, trembling in the balance, nodding to its fall, threatening, ominous, illomened, alarming, explosive, adventurous, incidit in Scyllam qui vult vitare Charybdim, nam tua res agitur paries dum proximus ardet.

Transientness

N transience, transientness, evanescence, impermanence, fugacity, caducity, mortality, span, nine days' wonder, bubble, Mayfly, spurt, flash in the pan, temporary arrangement, interregnum, velocity, suddenness, changeableness, transient, transient boarder, transient guest, transient, transitory, transitive, passing, evanescent, fleeting, cursory, short-lived, ephemeral, flying, fugacious, fugitive, shifting, slippery, spasmodic, instantaneous, momentaneous, temporal, temporary, provisional, provisory, deciduous, perishable, mortal, precarious, unstable, insecure, impermanent, brief, quick, brisk, extemporaneous, summary, pressed for time, sudden, momentary, temporarily, pro tempore, for the moment, for a time, awhile, en passant, in transitu, in a short time, soon, briefly, at short notice, on the point of, on the eve of, in articulo, between cup and lip, one's days are numbered, the time is up, here today and gone tomorrow, non semper erit aestas, eheu! fugaces labuntur anni, sic transit gloria mundi, a schoolboy's tale, the wonder of the hour!, dum loquimur fugerit invidia aetas, fugit hora, all that is transitory is but an illusion.

Changeableness

N changeableness, mutability, inconstancy, versatility, mobility, instability, unstable equilibrium, vacillation, fluctuation, vicissitude, alternation, restlessness, fidgets, disquiet, disquietude, inquietude, unrest, agitation, moon, Proteus, chameleon, quicksilver, shifting sands, weathercock, harlequin, Cynthia of the minute, April showers, wheel of Fortune, transientness, changeable, changeful, changing, mutable, variable, checkered, ever changing, protean, proteiform, versatile, unstaid, inconstant, unsteady, unstable, unfixed, unsettled, fluctuating, restless, agitated, erratic, fickle, irresolute, capricious, touch and go, inconsonant, fitful, spasmodic, vibratory, vagrant, wayward, desultory, afloat, alternating, alterable, plastic, mobile, transient, wavering, seesaw, off and on, a rolling stone gathers no moss, pictra mossa non fa muschis, honores mutant mores, varium et mutabile semper femina.