accidental, adrift, adventitious, afloat, agnostic, aleatory, alternating, ambiguous, amorphous, capricious, casual, causeless, chance, chancy, changeable, changeful, contingent, coquettish, destinal, desultory, deviable, dicey, dizzy, doubtful, doubting, dubious, eccentric, equivocal, erratic, extraordinary, faddish, fast and loose, fatal, fatidic, fickle, fitful, flickering, flighty, flirtatious, flitting, fluctuant, fluctuating, fluky, fortuitous, freakish, giddy, hesitant, hesitating, iffy, impetuous, improbable, impulsive, incalculable, incidental, inconsistent, inconstant, indecisive, indemonstrable, indeterminate, infirm, insecure, irregular, irresolute, irresponsible, light, mazy, mercurial, moody, more than expected, out-of-the-way, past expectation, polysemous, quicksilver, rambling, restless, risky, rocky, roving, scatterbrained, shaky, shapeless, shifting, shifty, shuffling, skeptical, skittish, spasmodic, spineless, sudden, tottery, touch-and-go, toying, treacherous, unaccountable, unannounced, unanticipated, uncaused, uncertain, unconfirmable, uncontrolled, unconvinced, undependable, undetermined, undisciplined, undivinable, undivined, unexpected, unfixed, unforeseeable, unforeseen, unguessed, unhealthy, unheralded, unhoped for, unlooked-for, unpersuaded, unpredicted, unprepared for, unprovable, unreliable, unrestrained, unsafe, unsettled, unsound, unstable, unstable as water, unstaid, unsteadfast, unsteady, unsure, untrustworthy, unverifiable, vacillating, vagrant, variable, versatile, vicissitudinary, vicissitudinous, volatile, wandering, wanton, wavering, wavery, wavy, wayward, whimsical, wishy-washy, without warning