hierarch vs pastor

hierarch

noun
  • One who has high and controlling authority in sacred things; the chief of a sacred order. 

  • A title of bishops in their role as ordinaries (arbiters of canon law) over their respective dioceses. 

pastor

noun
  • Someone with spiritual authority over a group of people 

  • A minister or priest in a church. 

  • A bird, the rosy starling. 

  • The main priest serving a parish. 

verb
  • To serve a congregation as pastor 

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