age vs eon

age and eon both are nouns.

Word	Noun	Adjective	Verb	Adverb
age	Yes	No	Yes	No
eon	Yes	No	No	No

As nouns, eon is a hyponym of age; that is, eon is a word with a more specific, narrower meaning than age:

Other hyponyms of age include month of Sundays, aeon, blue moon, year dot.

age (noun)	eon (noun)
how long something has existed	(Gnosticism) a divine power or nature emanating from the Supreme Being and playing various roles in the operation of the universe
a time of life (usually defined in years) at which some particular qualification or power arises	an immeasurably long period of time
a late time of life	the longest division of geological time
an era of history having some distinctive feature
a prolonged period of time