1. in a manner that shows indecision, uncertainty, or lack of firmness
He vacillatingly agreed to the proposal, unsure of his decision.
Ele concordou vacilantemente com a proposta, incerto de sua decisão.
2. in a way that fluctuates or wavers between two positions or opinions
She spoke vacillatingly about her future plans.
Ela falou vacilantemente sobre seus planos futuros.