Caucasian vs Caucasia

Caucasian and Caucasia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Caucasian	Yes	Yes	No	No
Caucasia	Yes	No	No	No

Caucasian (noun)	Caucasia (noun)
a number of languages spoken in the Caucasus that are unrelated to languages spoken elsewhere	a large region between the Black and Caspian seas that contains the Caucasus Mountains; oil is its major resource
a person of European descent with a light-skinned or pale complexion

Caucasian (adjective)	Caucasia (adjective)
of or relating to the geographical region of Caucasia
of or relating to Caucasian people