Elysium vs Elysian Fields

Elysium and Elysian Fields both are nouns.

Word	Noun	Adjective	Verb	Adverb
Elysium	Yes	No	No	No
Elysian Fields	Yes	No	No	No

As nouns, Elysium and Elysian Fields are synonyms defined as:

Elysium and Elysian Fields: (Greek mythology) the abode of the blessed after death

Elysium (noun)	Elysian Fields (noun)
(Greek mythology) the abode of the blessed after death	(Greek mythology) the abode of the blessed after death
a place or condition of ideal happiness