Hadean vs Plutonian

Hadean is a noun but Plutonian is not a noun.

Word	Noun	Adjective	Verb	Adverb
Hadean	Yes	Yes	No	No
Plutonian	No	Yes	No	No

As adjectives, Hadean and Plutonian are synonyms defined as:

Hadean and Plutonian: of or relating to or characteristic of Hades or Tartarus

Other synonyms of Hadean include Tartarean.

Hadean (noun)	Plutonian (noun)
the earliest eon in the history of the Earth from the first accretion of planetary material (around 4,600 million years ago) until the date of the oldest known rocks (about 3,800 million years ago); no evidence of life

Hadean (adjective)	Plutonian (adjective)
of or relating to or characteristic of Hades or Tartarus	of or relating to or characteristic of Hades or Tartarus