affair vs black box

affair

noun
  • A material object (vaguely designated). 

  • 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. 

black box

noun
  • A theoretical construct or device with known input and output characteristics but unknown method of operation. 

  • A flight recorder; the brightly colored cockpit voice recorders and flight data recorders in an aircraft designed to aid in determining the cause of an accident. 

  • A device used in phreaking that prevents the calling party from being billed for the call placed. 

  • A type of theater characterized by a lack of decoration or complex mechanisms. 

  • Any similar device on motor vehicles, such as rail event recorders and ship trip recorders. 

verb
  • To focus on the inputs and outputs without worrying about the internal complexity. 

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