acerbate vs acetous

acerbate

adj
  • Embittered; having a sour disposition or nature. 

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

acetous

adj
  • Having a sour taste; sour; acid. 

  • Causing, or connected with, acetification 

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