ca·liph also ca·lif or kha·lif 
(kālĭf, kălĭf)
(kālĭf, kălĭf)n.
A leader of an Islamic polity, regarded as a successor of Muhammad and by tradition always male.
[Middle English calife, from Old French, from Arabic ḫalīfa, successor (to Muhammad), caliph, from ḫalafa, to succeed; see ḫlp in the Appendix of Semitic roots.]
cali·phal adj.