Persia vs Persian

Persia and Persian both are nouns.

Word	Noun	Adjective	Verb	Adverb
Persia	Yes	No	No	No
Persian	Yes	Yes	No	No

Persia (noun)	Persian (noun)
a theocratic Islamic republic in the Middle East in western Asia; Iran was the core of the ancient empire that was known as Persia until 1935; rich in oil	the language of Persia (Iran) in any of its ancient forms
an empire in southern Asia created by Cyrus the Great in the 6th century BC and destroyed by Alexander the Great in the 4th century BC	a native or inhabitant of Iran

Persia (adjective)	Persian (adjective)
	of or relating to Iran or its people or language or culture