Western Church vs Church of Rome

Western Church and Church of Rome both are nouns.

Word	Noun	Adjective	Verb	Adverb
Western Church	Yes	No	No	No
Church of Rome	Yes	No	No	No

As nouns, Western Church and Church of Rome are synonyms defined as:

Western Church and Church of Rome: the Christian Church based in the Vatican and presided over by a pope and an episcopal hierarchy

Other synonyms of Western Church include Roman Catholic, Roman Catholic Church, Roman Church.

Western Church (noun)	Church of Rome (noun)
the Christian Church based in the Vatican and presided over by a pope and an episcopal hierarchy	the Christian Church based in the Vatican and presided over by a pope and an episcopal hierarchy