Japan vs Yeddo

Japan and Yeddo both are nouns.

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

Japan (noun)	Yeddo (noun)
a constitutional monarchy occupying the Japanese Archipelago; a world leader in electronics and automobile manufacture and ship building	the capital and largest city of Japan; the economic and cultural center of Japan
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