Caucasoid vs Caucasian

Caucasoid is not a noun while Caucasian is a noun.

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

As adjectives, Caucasoid and Caucasian are synonyms defined as:

Caucasoid (noun)	Caucasian (noun)
	a number of languages spoken in the Caucasus that are unrelated to languages spoken elsewhere
	a person of European descent with a light-skinned or pale complexion

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