ageless vs eonian

ageless and eonian both are adjectives.

Word	Noun	Adjective	Verb	Adverb
ageless	No	Yes	No	No
eonian	No	Yes	No	No

As adjectives, ageless and eonian are synonyms defined as:

Other synonyms of ageless include aeonian, eternal, everlasting, perpetual, unceasing, unending.

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