acerbate vs grump

acerbate

verb
  • To make bitter or sour. 

  • To exasperate; to irritate. 

adj
  • Embittered; having a sour disposition or nature. 

grump

verb
  • To be grumpy. 

  • To complain. 

noun
  • A grumpy mood. 

  • A habitually grumpy or complaining person. 

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