Holy Father vs pontiff

Holy Father and pontiff both are nouns.

Word	Noun	Adjective	Verb	Adverb
Holy Father	Yes	No	No	No
pontiff	Yes	No	No	No

As nouns, Holy Father and pontiff are synonyms defined as:

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

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