pope vs Roman Catholic Pope

pope and Roman Catholic Pope both are nouns.

Word	Noun	Adjective	Verb	Adverb
pope	Yes	No	No	No
Roman Catholic Pope	Yes	No	No	No

As nouns, pope and Roman Catholic Pope are synonyms defined as:

Other synonyms of pope include Bishop of Rome, Catholic Pope, Holy Father, pontiff, Vicar of Christ.

pope (noun)	Roman Catholic Pope (noun)
the head of the Roman Catholic Church	the head of the Roman Catholic Church