graduate student vs lector

graduate student

noun
  • A university student, usually already possessing a four-year degree, who is working on a master's degree or Ph.D. 

lector

noun
  • A public lecturer or reader at some universities. 

  • A person doing voice-over translation of foreign films, especially in Eastern European countries. 

  • A lay person who reads aloud certain religious texts in a church service. 

  • A person who reads aloud to workers to entertain them, appointed by a trade union. 

verb
  • To do a voice-over translation of a film. 

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