stun vs underwhelm

stun

verb
  • To shock or surprise. 

  • To hit the cue ball so that it slides without topspin or backspin (and with or without sidespin) and continues at a natural angle after contact with the object ball 

  • To incapacitate; especially by inducing disorientation or unconsciousness. 

noun
  • The effect on the cue ball where the ball is hit without topspin, backspin or sidespin. 

  • The condition of being stunned. 

  • A person who lacks intelligence. 

  • That which stuns; a shock; a stupefying blow. 

underwhelm

verb
  • To fail to impress; to perform disappointingly. 

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