Godan verb with 'ku' ending, Intransitive verb
to shake; to tremble; to sway; to flicker
ボートは波立つ水の上で揺れ動いた。The boat danced on the choppy water. to be unsettled; to be unstable; to fluctuate; to waver (e.g. between options); to vacillate; to seesaw
Also written ゆれ動く【ゆれうごく】