forbearance vs frustration

forbearance

noun
  • A refraining from the enforcement of something (as a debt, right, or obligation) that is due. 

  • Patient self-control; restraint and tolerance under provocation. 

frustration

noun
  • The state of contract that allows a party to back away from its contractual obligations due to (unforeseen) radical changes to the nature of the thing a party has been obligated to. 

  • A thing that frustrates. 

  • The feeling of annoyance at impassibility from resistance. 

  • The act of frustrating, or the state, or an instance of being frustrated. 

  • Anger not directed at anything or anyone in particular. 

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