unceasing vs eonian

unceasing and eonian both are adjectives.

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

As adjectives, unceasing and eonian are synonyms defined as:

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

unceasing (adjective)	eonian (adjective)
uninterrupted in time and indefinitely long continuing	of or relating to a geological eon (longer than an era)
continuing forever or indefinitely	continuing forever or indefinitely