Bishop of Rome vs Vicar of Christ

Bishop of Rome and Vicar of Christ both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bishop of Rome	Yes	No	No	No
Vicar of Christ	Yes	No	No	No

As nouns, Bishop of Rome and Vicar of Christ are synonyms defined as:

Bishop of Rome and Vicar of Christ: the head of the Roman Catholic Church

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

Bishop of Rome (noun)	Vicar of Christ (noun)
the head of the Roman Catholic Church	the head of the Roman Catholic Church