acerbation vs lamentation

acerbation

noun
  • Bitterness of feeling. 

  • Exacerbation, aggravation, deterioration. 

lamentation

noun
  • A sorrowful cry; a lament. 

  • Specifically, mourning. 

  • The act of lamenting. 

  • A group of swans. 

  • lamentatio, (part of) a liturgical Bible text (from the book of Job) and its musical settings, usually in the plural; hence, any dirge 

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