Synonyms and related words :
abnormal, adrift, afloat, alternating, amorphous, bereft of reason, birdbrained, birdwitted, brainsick, buoyant, capricious, changeable, changeful, coquettish, crackbrained, cracked, crazed, crazy, daft, deluded, demented, deprived of reason, deranged, desultory, deviable, dippy, disoriented, distraught, dizzy, dotty, eccentric, effervescent, empty-headed, erratic, faddish, fanciful, fast and loose, featherbrained, fickle, fitful, flickering, flirtatious, flitting, fluctuating, fluffy, freakish, frivolous, frothy, gay, giddy, hallucinated, harebrained, impetuous, impulsive, inconsistent, inconstant, indecisive, infirm, insane, irrational, irregular, irresolute, irresponsible, light, light-headed, lively, loco, lunatic, mad, maddened, manic, mazed, mazy, mental, mentally deficient, mercurial, meshuggah, moody, moon-struck, non compos, non compos mentis, not all there, not right, nutty, odd, of unsound mind, off, psycho, queer, quicksilver, rambling, rattlebrained, reasonless, reckless, restless, roving, scatterbrained, screwy, senseless, shallow, shallow-headed, shallow-minded, shallow-pated, shallow-witted, shapeless, shifting, shifty, shuffling, sick, silly, skittish, spasmodic, spineless, sprightly, stark-mad, stark-staring mad, strange, superficial, tetched, thoughtless, touched, toying, unaccountable, unbalanced, uncertain, uncontrolled, undependable, undisciplined, unfixed, unhinged, unpredictable, unprofound, unreliable, unrestrained, unsane, unsettled, unsound, unstable, unstable as water, unstaid, unsteadfast, unsteady, vacillating, vagrant, variable, versatile, vicissitudinary, vicissitudinous, volatile, wandering, wanton, wavering, wavery, wavy, wayward, whimsical, wild, wishy-washy, witless