quirk vs weakness

quirk

noun
  • An idiosyncrasy; a slight glitch, mannerism; something unusual about the manner or style of something or someone. 

  • An acute angle dividing a molding; a groove that runs lengthwise between the upper part of a moulding and a soffit. 

verb
  • To (cause to) move with a wry jerk. 

  • To furnish with a quirk or channel. 

weakness

noun
  • A special fondness or desire. 

  • An inadequate quality; fault 

  • The condition of being weak. 

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