Webster's Revised Unabridged Dictionary · 1913

Caliph

Caliph (kā"lif) , noun

[Old English caliphe, califfe, French calife (compare Sp. califa), from Arabic khalīfan successor, from khalafa to succed (that is a successor of Mohammed).]

Successor or vicar; the civil and religious leader of a Muslim state; -- a title of the successors of Mohammed both as temporal and spiritual rulers, used formerly by the sultans of Turkey.