apostolical vs pope

apostolical is not a noun while pope is a noun.

Word	Noun	Adjective	Verb	Adverb
apostolical	No	Yes	No	No
pope	Yes	No	No	No

apostolical (noun)	pope (noun)
	the head of the Roman Catholic Church

apostolical (adjective)	pope (adjective)
of or relating to or deriving from the Apostles or their teachings
proceeding from or ordered by or subject to a pope or the papacy regarded as the successor of the Apostles