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

regicide

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

oil baron

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

sceptre

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

rajah / (historical) Head of the Ryukyu Domain

crown prince

a surname