acerbate vs grouch

acerbate

verb
  • To make bitter or sour. 

  • To exasperate; to irritate. 

adj
  • Embittered; having a sour disposition or nature. 

grouch

verb
  • To be grumpy or irritable; to complain. 

noun
  • A complaint, a grumble, a fit of ill-humor. 

  • One who is grumpy or irritable. 

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