(Greek mythology, Roman mythology) Greco-Roman god of the underworld.

(astronomy) Originally known as the ninth planet in the solar system but reclassified in 2006 as a dwarf planet; the brightest and first known Kuiper belt object; represented by the symbol ♇ as a planet or as a dwarf planet in astronomy; both are used in astrology, where symbols are more common.

(neologism) To demote or devalue something.