basilica vs Roman basilica

basilica and Roman basilica both are nouns.

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

As nouns, basilica and Roman basilica are synonyms defined as:

basilica and Roman basilica: a Roman building used for public administration

basilica (noun)	Roman basilica (noun)
a Roman building used for public administration	a Roman building used for public administration
an early Christian church designed like a Roman basilica; or a Roman Catholic church or cathedral accorded certain privileges