Vicar of Christ vs Holy Father

Vicar of Christ and Holy Father both are nouns.

Word	Noun	Adjective	Verb	Adverb
Vicar of Christ	Yes	No	No	No
Holy Father	Yes	No	No	No

As nouns, Vicar of Christ and Holy Father are synonyms defined as:

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

Vicar of Christ (noun)	Holy Father (noun)
the head of the Roman Catholic Church	the head of the Roman Catholic Church