aeonian vs aeon

aeonian is not a noun while aeon is a noun.

Word	Noun	Adjective	Verb	Adverb
aeonian	No	Yes	No	No
aeon	Yes	No	No	No

aeonian (noun)	aeon (noun)
	(Gnosticism) a divine power or nature emanating from the Supreme Being and playing various roles in the operation of the universe
	an immeasurably long period of time
	the longest division of geological time

aeonian (adjective)	aeon (adjective)
of or relating to a geological eon (longer than an era)
continuing forever or indefinitely