aide-de-camp vs chamberlain

aide-de-camp

noun
  • A military officer who serves as an adjutant to a higher-ranking officer, prince or other high political dignitary. 

chamberlain

noun
  • A high officer of state, as currently with the papal camerlengo, but normally now a mainly honorary title. 

  • A senior royal official in charge of superintending the arrangement of domestic affairs and often charged with receiving and paying out money kept in the royal chamber, especially in the United Kingdom and in Denmark. 

How often have the words aide-de-camp and chamberlain occurred in a corpus of books? (source: Google Ngram Viewer )