incongruity vs mésalliance

incongruity

noun
  • The state of being incongruous, or lacking congruence. 

  • A thing that is incongruous. 

  • An instance or point of disagreement 

mésalliance

noun
  • Marriage with a person of inferior social position. 

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