acerbation vs umbrage

acerbation

noun
  • Bitterness of feeling. 

  • Exacerbation, aggravation, deterioration. 

umbrage

noun
  • A feeling of anger or annoyance caused by something offensive. 

  • A feeling of doubt. 

  • Leaves that provide shade, as the foliage of trees. 

verb
  • To shade. 

  • To displease or cause offense. 

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