to shake; to tremble; to sway; to flicker
to be unsettled; to be unstable; to fluctuate; to waver (e.g. between options); to vacillate; to seesaw
風に揺れ動く木々を眺めた。
I watched the trees swaying in the wind.
彼の気持ちが揺れ動いているのがわかった。
I could tell that his feelings were wavering.
世論が揺れ動く中、政府は新たな方針を打ち出した。
Amid wavering public opinion, the government announced a new policy.