Greco-Roman vs classic

Greco-Roman is not a noun while classic is a noun.

Word	Noun	Adjective	Verb	Adverb
Greco-Roman	No	Yes	No	No
classic	Yes	Yes	No	No

Greco-Roman (noun)	classic (noun)
	a creation of the highest excellence
	an artist who has created classic works

Greco-Roman (adjective)	classic (adjective)
of or pertaining to or characteristic of the ancient Greeks and Romans, especially their art, literature, or culture	of or relating to the first significant period of a civilization, culture, area of study, etc.
	considered of the highest quality and lasting significance or worth
	well-known and long-established in form or style
	of a well-known type; remarkably typical