| Noun | 1. | caliph - 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"swayer, ruler - a person who rules or commands; "swayer of the universe" Ali - the fourth caliph of Islam who is considered to be the first caliph by Shiites; he was a cousin and son-in-law of Muhammad; after his assination Islam was divided into Shiite and Sunnite sects | |