demesne vs regnum

demesne

noun
  • A region or area; a domain. 

  • A lord's chief manor place, with that part of the lands belonging thereto which has not been granted out in tenancy; a house, and the land adjoining, kept for the proprietor's own use. 

regnum

noun
  • A rank in the classification of organisms, below dominium and above divisio. 

  • A badge of royalty, especially the early form of the pope's tiara. 

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