The word Shia (Arabic: شيعة) literally means "followers" and is the short form of the historic phrase shīʻatu ʻAlī (شيعة علي /ˈʃiːʕatu ˈʕaliː/), meaning "followers of Ali", "faction of Ali", or "party of Ali". Shi'a, Shia, Shi'ism/Shi'ite or Shiism/Shiite are the forms used in English, for adherents, mosques, and things associated with the religion. Shi'i is the singular for of Shi'a.
The term was first used during Muhammad's life. At present, the word refers to the Muslims who believe that the leadership of the community after Muhammad belongs to Ali and his successors. Nawbakhti states that the term Shia refers to a group of Muslims that at the time of Muhammad and after him regarded Ali as the Imam and Caliph. Al-Shahrastani expresses that the term Shia refers to those who believe that Ali is designated as the Heir, Imam and caliph by Muhammad and that Ali's authority is maintained through his descendants. For the Shia, this conviction is implicit in the Quran and the history of Islam. Shia scholars emphasize that the notion of authority is linked to the family of the prophets as the verses 3:33,34 show: "Indeed, God chose Adam and Noah and the family of Abraham and the family of 'Imran over the worlds – (33) Descendants, some of them from others. And God is Hearing and Knowing. (34)"