baroness vs rex

baroness

noun
  • The wife of a baron. 

  • A woman holding a baronial title in her own right; a female ruler of a barony. 

rex

noun
  • An animal which has a genetic recessive variation that causes the guard hairs to be very short or fully lacking. 

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