national capital vs Wellington

national capital and Wellington both are nouns.

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

national capital (noun)	Wellington (noun)
the capital city of a nation	(19th century) a man's high tasseled boot
	the capital of New Zealand
	British general and statesman; he defeated Napoleon at Waterloo; subsequently served as Prime Minister (1769-1852)