Roman vs Romanic

Roman is a noun but Romanic is not a noun.

Word	Noun	Adjective	Verb	Adverb
Roman	Yes	Yes	No	No
Romanic	No	Yes	No	No

As adjectives, Roman and Romanic are synonyms defined as:

Roman and Romanic: of or relating to or derived from Rome (especially ancient Rome)

Roman (noun)	Romanic (noun)
a resident of modern Rome
an inhabitant of the ancient Roman Empire

Roman (adjective)	Romanic (adjective)
of or relating to or supporting Romanism	of or relating to or derived from Rome (especially ancient Rome)
of or relating to or derived from Rome (especially ancient Rome)
characteristic of the modern type that most directly represents the type used in ancient Roman inscriptions