severity vs silliness

severity

noun
  • The degree of something undesirable; badness or seriousness. 

  • The state of being severe. 

silliness

noun
  • That which is perceived as silly or frivolous. 

  • An act that is silly; a result of being silly. 

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