- a spiritual leader of Islam, claiming succession from Muhammad.
- any of the former Muslim rulers of Baghdad (until 1258) and of the Ottoman Empire (from 1571 until 1924).
- a variant spelling of caliph
- Islam the title of the successors of Mohammed as rulers of the Islamic world, later assumed by the Sultans of Turkey
late 14c., from Old French caliphe (12c., also algalife), from Medieval Latin califa, from Arabic khalifa “successor,” originally Abu-Bakr, who succeeded Muhammad in the role of leader of the faithful after the prophet’s death.