Roman Catholic Pope vs Vicar of Christ

Roman Catholic Pope and Vicar of Christ both are nouns.

Word	Noun	Adjective	Verb	Adverb
Roman Catholic Pope	Yes	No	No	No
Vicar of Christ	Yes	No	No	No

As nouns, Roman Catholic Pope and Vicar of Christ are synonyms defined as:

Roman Catholic Pope and Vicar of Christ: the head of the Roman Catholic Church

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

Roman Catholic Pope (noun)	Vicar of Christ (noun)
the head of the Roman Catholic Church	the head of the Roman Catholic Church