commoner vs rex

commoner

noun
  • A member of the common people who holds no title or rank. 

  • Someone who has a right over another's land. They hold common rights because of residence or land ownership in a particular manor, especially rights on common land. eg: centuries-old grazing rights 

  • Someone who is not of noble rank. 

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 commoner and rex occurred in a corpus of books? (source: Google Ngram Viewer )