acerbate vs discouraged

acerbate

adj
  • Embittered; having a sour disposition or nature. 

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

discouraged

adj
  • Having lost confidence or hope; dejected; disheartened. 

  • unrecommended; unprescribed. 

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