(1):

(v. i.) To move staggeringly or unsteadily from one side to the other; to vacillate; to move the manner of a rotating disk when the axis of rotation is inclined to that of the disk; - said of a turning or whirling body; as, a top wabbles; a buzz saw wabbles.

(2):

(n.) A hobbling, unequal motion, as of a wheel unevenly hung; a staggering to and fro.