出典:Wiktionary
The adjective is derived from Latin Plūtōnius (“of または relating to Pluto, Greek かつ Roman god of the underworld”) + -an (suffix forming adjectives). Plūtōnius is from Ancient Greek Πλουτώνιος (Ploutṓnios, “of または relating to Pluto”), from Πλούτων (Ploútōn, “Pluto”) (from πλοῦτος (ploûtos, “riches, wealth”) (ultimately from Proto-Indo-European *plew- (“to fly; to flow; to run”)) + -ων (-ōn)) + -ιος (-ios, suffix forming adjectives). The English word is cognate with Middle French plutonien (modern French plutonien).[1] The noun is derived from the adjective.
Plutonian (comparative more Plutonian, superlative most Plutonian)
From Pluto (“dwarf planet in the Solar System”) + -n- + -ian (suffix forming adjectives meaning ‘from, related to, または like’, または nouns meaning ‘one belonging to, relating to, または like’), probably influenced by Plutonian (“of または relating to Pluto, Greek かつ Roman god of the underworld”) (see etymology 1).
Plutonian (not comparable)
Plutonian (複数形 Plutonians)