encounter

A meeting, especially one that is unplanned or unexpected.

A hostile, often violent meeting; a confrontation, skirmish, or clash, as between combatants.

(sports) A match between two opposing sides.

(sexuality) A sexual encounter; sexual activity, especially unplanned or unexpected, between people not in a sexual relationship, that usually does not lead to the establishment of a relationship, and may or may not happen again. A sexual encounter could be consensual or non-consensual; in the latter case, it is a sexual assault. A consensual sexual encounter that happens only once is commonly known as a one-night stand.

(India) An extrajudicial killing or execution.