affair

noun

Etymology: 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.

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

   “a difficult affair to manage”

   “Responsibility is my affair, reciprocity is his.”

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

   “an affair of honor”

   “an affair of love”

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

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

   “This garden is a ramshackle affair.”

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

   “When Martin's wife found out about his affair with her best friend, she asked for a divorce.”

   “Mary had an affair with a woman from the gym.”

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

   “Jerry's girlfriend said she wanted to go steady, but she was in an affair with one of his team-mates.”

7. A person with whom someone has an adulterous relationship.

   “I was his affair and he was a little boy toy to me... Together it was our little scandal.”

   “Turns out she's married; he was her affair.”

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

   “She also guessed that Lady Gladstone had not told them the affair had been planned some time ago. “We are looking forward to visiting you on Friday, Lady Gladstone,” said Harriet. “Geoffrey thought I might have forgotten because you sent us your invitation such ages ago, but I said, 'My dear brother, how could I possibly forget an invitation from Lady Gladstone?'“ “How very odd,” commented the comte lazily. “Lady Gladstone was just telling us it was an impromptu affair.””

9. The (male or female) genitals.

   “... ſhe, with the greateſt effrontery imaginable, unbuttons his breeches, and removing his ſhirt, draws out his affair, ſo ſhrunk and diminiſh’d that I could not but remember the difference, now creſt-fallen, or just faintly lifting its head: but our experinc’d matron very ſoon, by chafing it with her hands, brought it to ſwell to that ſize and erection I had before ſeen it up to.”