grudge vs rancor

grudge

noun
  • Deep-seated and/or long-term animosity or ill will about something or someone, especially due to a past misdeed or mistreatment. 

verb
  • To be unwilling to give or allow (someone something). 

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 grudge and rancor occurred in a corpus of books? (source: Google Ngram Viewer )