footnote vs straightness

footnote

noun
  • An event of lesser importance than some larger event to which it is related. 

  • A qualification to the import of something. 

  • A short piece of text, often numbered, placed at the bottom of a printed page, that adds a comment, citation, reference etc, to a designated part of the main text. 

verb
  • To add footnotes to a text. 

straightness

noun
  • The result or product of being straight. 

  • The state or quality of being straight (especially in the sense of "heterosexual"). 

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