chatelain vs pursuivant

chatelain

noun
  • Synonym of castellan: the lord of a castle; a caretaker entrusted to oversee a castle for its lord. 

pursuivant

noun
  • A Grand Lodge Officer who guards the inner door during a meeting of the Grand Lodge 

  • A functionary of lower rank than a herald, but discharging similar duties; called also pursuivant at arms; an attendant of the heralds, e.g. in the College of Arms. 

  • A warrant officer. 

  • A royal messenger, (particularly) one with the authority to execute warrants. 

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