priest vs theologus

priest

noun
  • a religious clergyman (clergywoman, clergyperson) who is trained to perform services or sacrifices at a church or temple 

  • the highest office in the Aaronic priesthood 

  • a blunt tool, used for quickly stunning and killing fish 

verb
  • To ordain as a priest. 

theologus

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

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