Source : Webster's Revised Unabridged Dictionary (1913)

Caliph \Ca"liph\, n. [OE. caliphe, califfe, F. calife (cf. Sp.
   califa), fr. Ar. khal[=i]fan successor, fr. khalafa to
   succed.]
   Successor or vicar; -- a title of the successors of Mohammed
   both as temporal and spiritual rulers, now used by the
   sultans of Turkey. [Written also {calif}.]

Source : WordNet®

caliph
     n : the civil and religious leader of a Muslim state considered
         to be a representative of Allah on earth; "many radical
         Muslims believe a Khalifah will unite all Islamic lands
         and people and subjugate the rest of the world" [syn: {calif},
          {kaliph}, {kalif}, {khalif}, {khalifah}]