national capital vs Edo

national capital and Edo both are nouns.

Word	Noun	Adjective	Verb	Adverb
national capital	Yes	No	No	No
Edo	Yes	No	No	No

national capital (noun)	Edo (noun)
the capital city of a nation	the capital and largest city of Japan; the economic and cultural center of Japan
	a member of a west African people living in the tropical forest region of southern Nigeria