WordNet sense 1 (unsteady in gait as from infirmity or old age):

tottery

WordNet sense 2 (changing position or direction):

shifting

WordNet sense 3 (vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze):

shaky, trembling

WordNet sense 4 (having unpredictable ups and downs):

fluctuating

WordNet sense 5 (unsteady in speech or action):

faltering

WordNet sense 6 (not firmly or solidly positioned):

unfirm

WordNet sense 7 (not firmly placed or set or fastened):

unfixed