estate of the realm vs commonwealth

estate of the realm and commonwealth both are nouns.

Word	Noun	Adjective	Verb	Adverb
estate of the realm	Yes	No	No	No
commonwealth	Yes	No	No	No

estate of the realm (noun)	commonwealth (noun)
a major social class or order of persons regarded collectively as part of the body politic of the country (especially in the United Kingdom) and formerly possessing distinct political rights	a politically organized body of people under a single government
	a political system in which the supreme power lies in a body of citizens who can elect people to represent them
	a world organization of autonomous states that are united in allegiance to a central power but are not subordinate to it or to one another
	the official name of some states in the United States (Massachusetts and Pennsylvania and Virginia and Kentucky) and associated territories (Puerto Rico)