Honshu vs capital of Japan

Honshu and capital of Japan both are nouns.

Word	Noun	Adjective	Verb	Adverb
Honshu	Yes	No	No	No
capital of Japan	Yes	No	No	No

Honshu (noun)	capital of Japan (noun)
the central and largest of the four main islands of Japan; between the Sea of Japan and the Pacific Ocean; regarded as the Japanese mainland	the capital and largest city of Japan; the economic and cultural center of Japan