failure vs incapability

failure

noun
  • An object, person or endeavour in a state of failure or incapable of success. 

  • Omission to do something, whether or not it was attempted, especially something that ought to have been done. 

  • State or condition of not meeting a desirable or intended objective, opposite of success. 

  • Bankruptcy. 

  • Termination of the ability of an item to perform its required function; breakdown. 

incapability

noun
  • The condition of being incapable. 

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