Biblical: a priest who showed great courage during the reigns of the first three kings of Israel.
Means "righteous" in Hebrew.
Zadok, a "rapacious Jew" in The Unfortunate Traveller: or, the Life of JackWilton (1594) by Thomas Nashe
ZadokAllen, character from H.P. Lovecraft's The Shadow over Innsmouth
"Zadok the Priest", one of the four Coronation Anthems composed by George Frideric Handel for the coronation of George II in 1727, and sung at every coronation of a British sovereign since.