"Set opposition" generally refers to a state of conflict or disagreement between two sides, with both standing firm in their beliefs or goals. The antonyms for this phrase could include terms like cooperation, harmony, agreement, concord, or unity. When two parties work together towards a common goal, there is a decrease in the set opposition. Instead, the focus shifts towards creating a space for negotiation, compromise, and finding common ground. Collaboration, understanding, and empathy can also help to dissolve set opposition and promote peaceful coexistence. In this way, antonyms for "set opposition" represent the value of working together towards a peaceful resolution.