acerbate vs sicken

acerbate

verb
  • To make bitter or sour. 

  • To exasperate; to irritate. 

adj
  • Embittered; having a sour disposition or nature. 

sicken

verb
  • To fill with disgust or abhorrence. 

  • To become ill. 

  • To lower the standing of. 

  • To make ill. 

  • To be filled with disgust or abhorrence. 

  • To become disgusting or tedious. 

  • To become weak; to decay; to languish. 

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