burgomaster vs warden

burgomaster

noun
  • The mayor, or head magistrate, of a town in the Netherlands, Belgium, Germany and certain other countries. 

warden

noun
  • A governing official in various institutions 

  • An official charged with supervisory duties or with the enforcement of specific laws or regulations; such as a game warden or air-raid warden 

  • A variety of pear. 

  • A chief administrative officer of a prison. 

verb
  • To carry out the duties of a warden. 

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