eternal sleep vs quietus

eternal sleep and quietus both are nouns.

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

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

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

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

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