Synonyms and related words :
Adamic, abulic, adrift, afloat, afraid, ailing, alternating, amorphous, anile, backsliding, cachectic, capricious, carnal, changeable, changeful, cowardly, crabbed, crippled, crumbling, dangerous, debilitated, decrepit, desultory, deviable, disintegrating, dizzy, doddered, doddering, doddery, drained, eccentric, enervated, enfeebled, erratic, erring, exhausted, failing, faint, fainthearted, fallen, faltering, fast and loose, feeble, feebleminded, fickle, fitful, fleshly, flickering, flighty, flimsy, flitting, fluctuating, fossilized, fragile, frail, freakish, gerontal, gerontic, giddy, hazardous, healthless, ill, impetuous, impulsive, impure, in poor health, inconsistent, inconstant, indecisive, indisposed, insecure, insubstantial, invalid, invertebrate, irregular, irresolute, irresponsible, lame, languishing, lapsed, mazy, mercurial, moody, moribund, mossbacked, moth-eaten, mummylike, of easy virtue, on the decline, pale, palsied, papery-skinned, peaked, peaky, peccable, perilous, pliable, poor, poorish, postlapsarian, precarious, prodigal, provisional, rambling, ravaged with age, recidivist, recidivistic, reduced, reduced in health, restless, rickety, risky, rotten, rotten at, roving, run to seed, run-down, rusty, scatterbrained, senile, shaky, shapeless, shifting, shifty, shriveled, shuffling, sick, sickly, slippery, soft, spasmodic, spineless, stricken in years, temporary, tentative, ticklish, timeworn, tottering, tottery, treacherous, unaccountable, unangelic, uncertain, unchaste, unclean, uncontrolled, undependable, undisciplined, unfaithworthy, unfirm, unfixed, ungodly, ungood, unhealthy, unpredictable, unreliable, unrestrained, unrighteous, unsaintly, unsettled, unsolid, unsound, unstable, unstable as water, unstaid, unsteadfast, unsteady, unsturdy, unsubstantial, unsure, untrustworthy, unvirtuous, unwell, vacillating, vagrant, valetudinarian, valetudinary, variable, vicissitudinary, vicissitudinous, virtueless, volatile, wandering, wanton, wasted, wavering, wavery, wavy, wayward, weak, weak-kneed, weak-minded, weak-willed, weakened, weakly, whimsical, wishy-washy, with low resistance, withered, wizened, wobbling, wobbly