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"
• (military) An action or engagement not of sufficient magnitude to be called a battle.
• (slang, now rare) 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."