acerbity vs score-settling

acerbity

noun
  • Something harsh (e.g. a remark, act or experience). 

  • Harshness, bitterness, or severity 

  • Sourness of taste, with bitterness and astringency, like that of unripe fruit. 

score-settling

noun
  • Synonym of revenge 

How often have the words acerbity and score-settling occurred in a corpus of books? (source: Google Ngram Viewer )