acerbate vs begrudge

acerbate

verb
  • To make bitter or sour. 

  • To exasperate; to irritate. 

adj
  • Embittered; having a sour disposition or nature. 

begrudge

verb
  • To grudge about or over; be envious or covetous. 

  • To give reluctantly. 

  • To be reluctant. 

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