affair
n. countablen. a situation or event that is usually complicated or private. It can also mean a secret romantic relationship between two people when at least one of them is married.
n. a matter, event, or set of circumstances, often of a complex or scandalous nature. Also refers to a sexual relationship between two people, typically where one or both are already in a committed relationship.
The whole situation was a very messy affair.
The local government's handling of the new park project became a public affair after the budget doubled.
What began as a minor administrative error soon spiraled into a national affair, involving multiple departments and leading to several high-profile resignations.
From Middle English afere, affere, from Old French afaire, from a- + faire (“to do”), from Latin ad- + facere (“to do”). See fact, and compare ado.
Often modified by adjectives like 'private', 'public', or 'romantic' to specify the nature of the event.