quirk vs trait

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. 

trait

noun
  • An identifying characteristic, habit or trend. 

  • An uninstantiable collection of methods that provides functionality to a class by using the class’s own interface. 

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