demesne vs real estate

demesne and real estate both are nouns.

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

As nouns, real estate is a hypernym of demesne; that is, real estate 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 estate: property consisting of houses and land

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

demesne (noun)	real estate (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