eternal sleep vs sleep

eternal sleep and sleep both are nouns.

Word	Noun	Adjective	Verb	Adverb
eternal sleep	Yes	No	No	No
sleep	Yes	No	Yes	No

As nouns, eternal sleep and sleep are synonyms defined as:

eternal sleep and sleep: euphemisms for death (based on an analogy between lying in a bed and in a tomb)

Other synonyms of eternal sleep include eternal rest, quietus, rest.

eternal sleep (noun)	sleep (noun)
euphemisms for death (based on an analogy between lying in a bed and in a tomb)	a natural and periodic state of rest during which consciousness of the world is suspended
	euphemisms for death (based on an analogy between lying in a bed and in a tomb)
	a torpid state resembling deep sleep
	a period of time spent sleeping

eternal sleep (verb)	sleep (verb)
	be asleep
	be able to accommodate for sleeping