"Alcibiades . . . was too unsteady, and (according to Mr. Coleridge's coinage) “unreliable;” or perhaps, in more correct English, too “unrelyuponable.”" [1913 Webster]

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OXFORD DICTIONARY

unreliable, adj. not reliable; erratic.

Derivative

unreliability n. unreliableness n. unreliably adv.

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THESAURUS

unreliable

adrift, afloat, alternating, amorphous, capricious, changeable, changeful, coquettish, dangerous, desultory, deviable, disreputable, dizzy, doubtful, dubious, eccentric, erratic, faddish, faithless, false, falsehearted, fast and loose, fickle, fitful, flickering, flighty, flimsy, flirtatious, flitting, fluctuating, fly-by-night, freakish, garbled, giddy, hazardous, impetuous, impulsive, inaccurate, inauthentic, inconsistent, inconstant, indecisive, inexact, infirm, insecure, insubstantial, irregular, irresolute, irresponsible, light, mazy, mercurial, miscited, misquoted, misreported, misstated, moody, perfidious, perilous, precarious, provisional, questionable, quicksilver, rambling, restless, risky, rocky, roving, scatterbrained, shaky, shapeless, shifting, shifty, shuffling, skittish, slick, slippery, spasmodic, spineless, spurious, temporary, tentative, ticklish, tottery, toying, treacherous, tricky, trustless, unaccountable, unassured, unauthentic, unauthoritative, uncertain, uncontrolled, undependable, undisciplined, unfaithful, unfaithworthy, unfixed, unfounded, unhealthy, unpredictable, unrestrained, unsafe, unsettled, unsolid, unsound, unstable, unstable as water, unstaid, unsteadfast, unsteady, unsubstantial, unsure, untrue, untrustworthy, untrusty, vacillating, vagrant, variable, versatile, vicissitudinary, vicissitudinous, volatile, wandering, wanton, wavering, wavery, wavy, wayward, weak, whimsical, wishy-washy, workaday

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ROGET THESAURUS

unreliable

Uncertainty

N uncertainty, incertitude, doubt, doubtfulness, dubiety, dubitation, dubitancy, dubitousness, hesitation, suspense, perplexity, embarrassment, dilemma, bewilderment, timidity, vacillation, diaporesis, indetermination, vagueness, haze, fog, obscurity, ambiguity, contingency, dependence, dependency, double contingency, possibility upon a possibility, open question, onus probandi, blind bargain, pig in a poke, leap in the dark, something or other, needle in a haystack, needle in a bottle of hay, roving commission, precariousness, fallibility, uncertain, casual, random, changeable, doubtful, dubious, indecisive, unsettled, undecided, undetermined, in suspense, open to discussion, controvertible, in question, vague, indeterminate, indefinite, ambiguous, equivocal, undefined, undefinable, confused, mystic, oracular, dazed, perplexing, enigmatic, paradoxical, apocryphal, problematical, hypothetical, experimental, unpredictable, unforeseeable (unknowable), fallible, questionable, precarious, slippery, ticklish, debatable, disputable, unreliable, untrustworthy, contingent, contingent on, dependent on, subject to, dependent on circumstances, occasional, provisional, unauthentic, unauthenticated, unauthoritative, unascertained, unconfirmed, undemonstrated, untold, uncounted, in a state of uncertainty, in a cloud, in a maze, bushed, off the track, ignorant, afraid to say, out of one's reckoning, astray, adrift, at sea, at fault, at a loss, at one's wit's end, at a nonplus, puzzled, lost, abroad, d_esorient_e, distracted, distraught, pendente lite, sub spe rati, Heaven knows, who can tell? who shall decide when doctors disagr.

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