A descendant of ‘Alī, or a supporter of the claims of his descendants to the Caliphate; one who believes ʿAlī to be the true successor of Muhammad; a Shiite. Also (and in earliest use) attributive.
Origin
Mid 18th century; earliest use found in Joseph Morgan (fl. 1707–1739), historian. From the name of ʿAlīibn Abī Ṭālib (598–661), son-in-law and cousin of the prophet Muhammad, and fourth Caliph + -id.