lector vs thesaurus

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. 

thesaurus

noun
  • A publication, traditionally in the form of a book and now often online, that provides synonyms (and sometimes antonyms and other semantic relations) for the words of a given language. 

  • A hierarchy of subject headings — canonic titles of themes and topics, the titles serving as search keys. 

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