demesne vs real property

demesne and real property both are nouns.

Word	Noun	Adjective	Verb	Adverb
demesne	Yes	No	No	No
real property	Yes	No	No	No

As nouns, real property is a hypernym of demesne; that is, real property is a word with a broader meaning than demesne:

demesne: extensive landed property (especially in the country) retained by the owner for his own use
real property: property consisting of houses and land

Other hypernyms of demesne include immovable, real estate, realty.

demesne (noun)	real property (noun)
territory over which rule or control is exercised	property consisting of houses and land
extensive landed property (especially in the country) retained by the owner for his own use