interrogatory vs third degree

interrogatory

noun
  • A question; an interrogation. 

  • A formal question submitted to opposing party to answer, generally governed by court rule. 

adj
  • Serving to interrogate; questioning. 

third degree

noun
  • Intensive rough interrogation in order to extract information or a confession 

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