foible vs frailty

foible

noun
  • A weakness or failing of character. 

  • A quirk, idiosyncrasy, or mannerism; an unusual habit that is slightly strange or silly. 

  • Part of a sword between the middle and the point, weaker than the forte. 

frailty

noun
  • A fault proceeding from weakness; foible; sin of infirmity. 

  • The condition quality of being frail, physically, mentally, or morally; weakness of resolution; liability to be deceived. 

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