the King of the Underworld; either Hades/Pluto in ancient Greco-Roman mythology or King Yama in Hindu-Buddhist belief.

(shogi) free king, queen (a piece in chu shogi, dai shogi and larger shogi variants)

(obsolete) Oakland (a city in Alameda, California, United States) / (historical) Ryukyuan royal administration (government)

crown prince

rajah / (historical) Head of the Ryukyu Domain

viceroy; one who governs a country, province, or colony as the representative of a monarch.

sceptre

oil baron

pretender to the position of king

(neologism, uncommon) a prince consort (husband of queen)