Honshu vs Japan

Honshu and Japan both are nouns.

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

Honshu (noun)	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	a constitutional monarchy occupying the Japanese Archipelago; a world leader in electronics and automobile manufacture and ship building
	a string of more than 3,000 islands to the east of Asia extending 1,300 miles between the Sea of Japan and the western Pacific Ocean