demesne vs signory

demesne and signory both are nouns.

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

As nouns, signory is a hyponym of demesne; that is, signory 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
signory: the estate of a seigneur

demesne (noun)	signory (noun)
territory over which rule or control is exercised	the estate of a seigneur
extensive landed property (especially in the country) retained by the owner for his own use