A legendary medieval Christian king of Asia, said to have defeated the Muslims and to be destined to bring help to the Holy Land.
祭司王约翰（传说中的中世纪亚洲基督徒国王，据说曾打败过穆斯林并预定要援助圣地）
Origin
Middle English: from Old French prestre Jehan, from medieval Latin presbyter Johannes 'priest John'.
Definition of Prester John in US English:
Prester John
proper nounˌprestər ˈjän
A legendary medieval Christian king of Asia (and, later, of Ethiopia), said to have defeated the Muslims and to be destined to bring help to the Holy Land.
祭司王约翰（传说中的中世纪亚洲基督徒国王，据说曾打败过穆斯林并预定要援助圣地）
Origin
Middle English: from Old French prestre Jehan, from medieval Latin presbyter Johannes ‘priest John’.