expectation vs possibility

expectation

noun
  • The prospect of the future; grounds upon which something excellent is expected to occur; prospect of anything good to come, especially of property or rank. 

  • The act or state of expecting or looking forward to an event as about to happen. 

  • The value of any chance (as the prospect of prize or property) which depends upon some contingent event. 

  • The first moment; the long-run average value of a variable over many independent repetitions of an experiment. 

  • The arithmetic mean. 

  • The leaving of a disease principally to the efforts of nature to effect a cure. 

  • That which is expected or looked for. 

possibility

noun
  • An option or choice, usually used in context with future events. 

  • The quality of being possible. 

  • A thing possible; that which may take place or come into being. 

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