national capital vs Ankara

national capital and Ankara both are nouns.

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

national capital (noun)	Ankara (noun)
the capital city of a nation	the capital of Turkey; located in west-central Turkey; it was formerly known as Angora and is the home of Angora goats