acerbate vs chafe

acerbate

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

adj
  • Embittered; having a sour disposition or nature. 

chafe

verb
  • To excite passion or anger in; to fret; to irritate. 

  • To have a feeling of vexation; to be vexed; to fret; to be irritated. 

  • To be worn by rubbing. 

  • To excite heat in by friction; to rub in order to stimulate and make warm. 

  • To fret and wear by rubbing. 

  • To rub; to come together so as to wear by rubbing; to wear by friction. 

noun
  • Injury or wear caused by friction. 

  • Vexation; irritation of mind; rage. 

  • Heat excited by friction. 

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