St. Irenaeus vs Roman Catholic

St. Irenaeus and Roman Catholic both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Irenaeus	Yes	No	No	No
Roman Catholic	Yes	Yes	No	No

St. Irenaeus (noun)	Roman Catholic (noun)
Greek theologian who was bishop of Lyons and an antiheretical writer; a saint and Doctor of the Church (circa 130-200)	the Christian Church based in the Vatican and presided over by a pope and an episcopal hierarchy
	a member of the Roman Catholic Church

St. Irenaeus (adjective)	Roman Catholic (adjective)
	of or relating to or supporting Romanism