acerbate vs ire

acerbate

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

adj
  • Embittered; having a sour disposition or nature. 

ire

verb
  • To anger, to irritate. 

noun
  • Great anger; wrath; keen resentment. 

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