Holy Father vs Catholic Pope

Holy Father and Catholic Pope both are nouns.

Word	Noun	Adjective	Verb	Adverb
Holy Father	Yes	No	No	No
Catholic Pope	Yes	No	No	No

As nouns, Holy Father and Catholic Pope are synonyms defined as:

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

Holy Father (noun)	Catholic Pope (noun)
the head of the Roman Catholic Church	the head of the Roman Catholic Church