presbyter vs theologus

presbyter

noun
  • An elder, priest, pastor, or minister in various Christian churches. 

  • An elder of the Presbyterian church. 

  • An elder of the congregation in early Christianity. 

theologus

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

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