Olympic vs Olympian

Olympic is not a noun while Olympian is a noun.

Word	Noun	Adjective	Verb	Adverb
Olympic	No	Yes	No	No
Olympian	Yes	Yes	No	No

As adjectives, Olympic and Olympian are synonyms defined as:

Olympic and Olympian: of the region of Olympia in Greece or its inhabitants

Olympic (noun)	Olympian (noun)
	an athlete who participates in the Olympic games
	a classical Greek god after the overthrow of the Titans

Olympic (adjective)	Olympian (adjective)
of or relating to the Olympic Games	of or pertaining to the greater gods of ancient Greece whose abode was Mount Olympus
of the region of Olympia in Greece or its inhabitants	of the region of Olympia in Greece or its inhabitants