Pluto

Pluto comes from Middle English Pluto, from Latin Plūtō, from Ancient Greek Πλούτων (Ploútōn, 'god of the underworld'), which was built from πλοῦτος (ploûtos, 'wealth') plus a suffix -ων (-ōn).

The name started as a word tied to riches, became the title of the Greek underworld god, passed into Latin and Middle English, and later was suggested by Venetia Burney as the name for the celestial body Pluto.

Pluto is a doublet of Plouton, both descending from the same Greek root ploûtos meaning wealth.