unsteady

convulsive, sudden, violent

broken, disconnected, fragmentary, interrupted

aimless, arbitrary, desultory, haphazard, hit-and-miss, hit-or-miss, odd, random, scattered, slapdash, stray

capricious, changeful, changing, flickery, fluctuating, fluid, inconstant, mercurial, mutable, temperamental, uncertain, unpredictable, unsettled, unstable, varying, wavering

changeable, fickle, variable, volatile

aimless, arbitrary, desultory, erratic, haphazard, hit-or-miss, irregular, random, scattered, slapdash, stray

ambivalent, hesitating, shaky, shilly-shally, shilly-shallying, vacillating, wavering

dicey, undependable, unreliable, untrustworthy

adaptable, mobile, protean, versatile

rocky, shaky, tippy, tipsy, wavery, wobbly (also wabbly), wonky [British]

infirm, insecure, precarious, unsound

doddering, doddery, jiggling, jiggly, rickety, staggery, teetering, tottering, tottery

askew, awry, cockeyed, lopsided, off-kilter, uneven

capricious, changeable, changeful, choppy, fickle, fluid, inconsistent, inconstant, mercurial, mutable, uncertain, unsettled, variable, volatile