Saint Irenaeus vs St. Irenaeus

Saint Irenaeus and St. Irenaeus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Saint Irenaeus	Yes	No	No	No
St. Irenaeus	Yes	No	No	No

As nouns, Saint Irenaeus and St. Irenaeus are synonyms defined as:

Saint Irenaeus and St. Irenaeus: Greek theologian who was bishop of Lyons and an antiheretical writer; a saint and Doctor of the Church (circa 130-200)

Other synonyms of Saint Irenaeus include Irenaeus.

Saint Irenaeus (noun)	St. Irenaeus (noun)
Greek theologian who was bishop of Lyons and an antiheretical writer; a saint and Doctor of the Church (circa 130-200)	Greek theologian who was bishop of Lyons and an antiheretical writer; a saint and Doctor of the Church (circa 130-200)