affair vs moot point

affair

noun
  • 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. 

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

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

  • A material object (vaguely designated). 

moot point

noun
  • An issue that is subject to, or open for, discussion or debate, to which no satisfactory answer is found; originally, one to be definitively determined by an assembly of the people. 

  • An issue regarded as potentially debatable, but no longer practically applicable. Although the idea may still be worth debating and exploring academically, and such discussion may be useful for addressing similar issues in the future, the idea has been rendered irrelevant for the present issue. 

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