demesne vs Crown land

demesne and Crown land both are nouns.

Word	Noun	Adjective	Verb	Adverb
demesne	Yes	No	No	No
Crown land	Yes	No	No	No

As nouns, Crown land is a hyponym of demesne; that is, Crown land is a word with a more specific, narrower meaning than demesne:

demesne: extensive landed property (especially in the country) retained by the owner for his own use
Crown land: land that belongs to the Crown

demesne (noun)	Crown land (noun)
territory over which rule or control is exercised	land that belongs to the Crown
extensive landed property (especially in the country) retained by the owner for his own use