impropriety vs misnomer

impropriety

noun
  • Improper language. 

  • The condition of being improper. 

  • An improper act. 

misnomer

noun
  • A use of a term that is misleading; a misname. 

  • something asserted not to be true; a myth or mistaken belief 

  • A term whose sense in common usage conflicts with a technical sense. 

  • A term that is misleading, even if it may not be incorrect. 

verb
  • To use a misleading term; to misname. 

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