affaire d'honneur vs feud

affaire d'honneur

noun
  • A duel. 

feud

noun
  • A staged rivalry between wrestlers. 

  • A state of long-standing mutual hostility. 

  • An estate granted to a vassal by a feudal lord in exchange for service. 

verb
  • To carry on a feud. 

How often have the words affaire d'honneur and feud occurred in a corpus of books? (source: Google Ngram Viewer )