be against, object to, disapprove of, be in opposition to, be not in favor of, disagree with, take issue with, be hostile to, be averse to, be antithetical to
resist - withstand - defy - confront - counter - contest - dispute - challenge - fight - combat - be against - stand against - stand up to - take a stand against
To oppose means to act against something or someone, often because you disagree with their ideas, decisions, or actions. It can describe political resistance to policies, personal disagreement with a plan, or active efforts to stop or change a proposal. To oppose may involve speaking out, voting against, protesting, or using other forms of action to prevent something from happening or continuing. The term can apply to individuals, groups, or institutions that stand in the way of another’s goals or intentions, emphasizing contrast, conflict, or clear refusal to support.