fortitude vs sufferance

fortitude

noun
  • Mental or emotional strength that enables courage in the face of adversity. 

sufferance

noun
  • Acquiescence or tacit compliance with some circumstance, behavior, or instruction. 

  • A permission granted by the customs authorities for the shipment of goods. 

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