affair

noun

• (often in the plural) Something which is done or is to be done; business of any kind, commercial, professional, or public.

  "a difficult affair to manage"

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

  "an affair of honor, a duel;  an affair of love, an intrigue"

• An action or engagement not of sufficient magnitude to be called a battle.
• A material object (vaguely designated).

  "He used a hook-shaped affair with a long handle to unlock the car."

• An adulterous relationship. (from affaire de cœur).
• A romantic relationship 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.