affair vs happening

affair

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

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

  • An adulterous relationship (from affaire de cœur, affair of the heart). 

  • A person with whom someone has an adulterous relationship. 

  • A romantic relationship with someone who is not one's regular partner (boyfriend, girlfriend). 

  • 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. 

  • A material object (vaguely designated). 

happening

noun
  • A spontaneous or improvised event, especially one that involves audience participation. 

  • Something that happens. 

adj
  • Trendy, up-to-the-minute. 

  • Busy, lively; vibrant, dynamic; fashionable. 

How often have the words affair and happening occurred in a corpus of books? (source: Google Ngram Viewer )