St. Irenaeus vs Saint Irenaeus

St. Irenaeus and Saint Irenaeus both are nouns.

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

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

St. Irenaeus and Saint 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 St. Irenaeus include Irenaeus.

St. Irenaeus (noun)	Saint 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)