indigestible vs smarting

indigestible

adj
  • Difficult to accept; unpalatable. 

  • Difficult or impossible to digest. 

noun
  • Anything that is difficult to digest. 

smarting

adj
  • Experiencing emotional pain or embarrassment. 

  • Painful, sore. 

noun
  • A sensation that smarts or stings. 

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