the Muslim messiah, an expected spiritual and temporal ruler destined to establish a reign of righteousness throughout the world.
2.
any of various claimants to this role, especially Muhammad Ahmed, who established an independent government in the Anglo-Egyptian Sudan that lasted until 1898.
Origin: 1790–1800; < Arabic mahdīy he who is guided
1792, from Arabic mahdiy, lit. "he who is guided aright," pp. of hada "to lead in the right way." Spiritual and temporal leader expected by some Muslims. Applied c.1880 to insurrectionary leaders in the Sudan who claimed to be him.