plantation vs demesne

plantation and demesne both are nouns.

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

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

plantation: an estate where cash crops are grown on a large scale (especially in tropical areas)
demesne: extensive landed property (especially in the country) retained by the owner for his own use

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

plantation (noun)	demesne (noun)
garden consisting of a small cultivated wood without undergrowth	territory over which rule or control is exercised
an estate where cash crops are grown on a large scale (especially in tropical areas)	extensive landed property (especially in the country) retained by the owner for his own use