timelessness vs eternity

timelessness and eternity both are nouns.

Word	Noun	Adjective	Verb	Adverb
timelessness	Yes	No	No	No
eternity	Yes	No	No	No

As nouns, timelessness and eternity are synonyms defined as:

timelessness and eternity: a state of eternal existence believed in some religions to characterize the afterlife

Other synonyms of timelessness include timeless existence.

timelessness (noun)	eternity (noun)
The property of not being restricted to a particular time or date.	a state of eternal existence believed in some religions to characterize the afterlife
a state of eternal existence believed in some religions to characterize the afterlife	time without end
	a seemingly endless time interval (waiting)