rancor vs resentment

rancor

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

  • Rancidity, rankness. 

resentment

noun
  • Anger or displeasure stemming from belief that one has been wronged or betrayed by others; indignation. 

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