duchess vs grand dukedom

duchess

noun
  • The wife or widow of a duke. 

  • The female ruler of a duchy. 

verb
  • to court or curry favour for political or business advantage; to flatter obsequiously. 

grand dukedom

noun
  • The title of grand duke or grand duchess, with its pertaining privileges and obligations; contrast grand duchy. 

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