Caucasus vs Caucasic

Caucasus is a noun but Caucasic is not a noun.

Word	Noun	Adjective	Verb	Adverb
Caucasus	Yes	No	No	No
Caucasic	No	Yes	No	No

Caucasus (noun)	Caucasic (noun)
a large region between the Black and Caspian seas that contains the Caucasus Mountains; oil is its major resource
the mountain range in Caucasia between the Black Sea and the Caspian Sea that forms part of the traditional border between Europe and Asia

Caucasus (adjective)	Caucasic (adjective)
	of or relating to the geographical region of Caucasia