kindness vs rancor

kindness

noun
  • The state of being kind. 

  • An instance of kind or charitable behaviour. 

rancor

noun
  • A feeling of long-lasting ire for another, sometimes to the point of hatred, over a perceived wrongdoing; bitterness. 

  • Rancidity, rankness. 

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