acerbate vs mean-spirited

acerbate

adj
  • Embittered; having a sour disposition or nature. 

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

mean-spirited

adj
  • Having a base, nasty, petty, or malevolent disposition. 

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