The term "run-in" typically refers to a hostile or argumentative encounter between two people. Antonyms for "run-in" could include peaceful, friendly, amicable, harmonious, congenial, agreeable, pleasant, and cooperative. These antonyms convey a sense of positivity and agreement rather than confrontation and conflict. In situations where a "run-in" is expected or anticipated, it is better to substitute these antonyms for a more diplomatic approach. Using language that promotes positive interactions can lead to smoother and more productive conversations. Choosing the right words can shift the tone of the entire conversation, resulting in a more favorable outcome.