What is the meaning of Affair?

Something which is done or is to be done; business of any kind, commercial, professional, or public.

Any proceeding or action which it is wished to refer to or characterize vaguely.

An action or engagement not of sufficient magnitude to be called a battle.

A material object (vaguely designated).

An adulterous relationship, chiefly of a married person. (from affaire de cœur, affair of the heart).

An otherwise illicit romantic relationship, such as with someone who is not one's regular partner (boyfriend, girlfriend).

A person with whom someone has an adulterous relationship.

A party or social gathering, especially of a formal nature.

The (male or female) genitals.

affair (extramarital relationship)

Source: wiktionary.org