means To move with small, quick, repeated motions from side to side or up and down.

from From the Middle Low German or Dutch 'wiggelen,' to totter or move unsteadily, related to the verb 'wag.' It belongs to a whole wobbly family of W-words — wiggle, waggle, wobble, wag — that English seems to have built by imitation, the sound of something that won't quite stay put.