manor vs demesne

manor and demesne both are nouns.

Word	Noun	Adjective	Verb	Adverb
manor	Yes	No	No	No
demesne	Yes	No	No	No

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

manor: the landed estate of a lord (including the house on it)
demesne: extensive landed property (especially in the country) retained by the owner for his own use

Other hypernyms of manor include acres, estate, land, landed estate.

manor (noun)	demesne (noun)
the mansion of a lord or wealthy person	territory over which rule or control is exercised
the landed estate of a lord (including the house on it)	extensive landed property (especially in the country) retained by the owner for his own use