pontiff vs theologus

pontiff

noun
  • A bishop of the early Church; now specifically, the Pope. 

  • Any chief figure or leader of a religion. 

  • A member of the most illustrious of the colleges of priests of the Roman religion, the College of Pontiffs; a pontifex. 

theologus

noun
  • Synonym of theologian (“Roman Catholic lecturer”) 

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