Saint Andrew the Apostle vs St. Andrew

Saint Andrew the Apostle and St. Andrew both are nouns.

Word	Noun	Adjective	Verb	Adverb
Saint Andrew the Apostle	Yes	No	No	No
St. Andrew	Yes	No	No	No

As nouns, Saint Andrew the Apostle and St. Andrew are synonyms defined as:

Saint Andrew the Apostle and St. Andrew: (New Testament) disciple of Jesus; brother of Peter; patron saint of Scotland

Other synonyms of Saint Andrew the Apostle include Andrew, Saint Andrew.

Saint Andrew the Apostle (noun)	St. Andrew (noun)
(New Testament) disciple of Jesus; brother of Peter; patron saint of Scotland	(New Testament) disciple of Jesus; brother of Peter; patron saint of Scotland