warden vs warrant officer

warden

noun
  • A chief administrative officer of a prison. 

  • 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 governing official in various institutions 

verb
  • To carry out the duties of a warden. 

warrant officer

noun
  • An officer assigned to execute warrants and other writs. 

  • An officer holding rank by virtue of a warrant rather than a commission. 

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