foible vs idiosyncrasy

foible

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

  • A weakness or failing of character. 

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

idiosyncrasy

noun
  • A behavior or way of thinking that is characteristic of a person. 

  • A peculiar individual reaction to a generally innocuous substance or factor. 

  • A peculiarity that serves to distinguish or identify. 

  • A language or behaviour that is particular to an individual or group. 

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