affair vs operation

affair

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

  • 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). 

  • 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). 

operation

noun
  • A business or organization. 

  • The method or practice by which actions are done. 

  • The act or process of operating; agency; the exertion of power, physical, mechanical, or moral. 

  • A procedure for generating a value from one or more other values (the operands); 

  • A military campaign (e.g. Operation Desert Storm) 

  • A planned undertaking. 

  • a function which maps zero or more (but typically two) operands to a single output value. 

  • The method by which a device performs its function. 

  • A surgical procedure. 

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