'Abbāsids: dynasty of caliphs (132/749–656/1258), descendants from the uncle of the Prophet Muḥammad, al-'Abbās b. 'Abd al-Muṭṭalib.

Aghlabids: dynasty (184/800–296/909) that ruled part of North Africa prior to the advent of the Fāṭimids.

Ahl al-Bayt: lit. the people of the house; the Prophet's household, typically including in Shī'ī context: Muḥammad, 'Alī, Fāṭima, al-Ḥasan, al-Ḥusayn and their progeny.

ahl al-dhimma: see dhimmī (q.v.).

'Alīds: the descendants of 'Alī b. Abī Ṭālib, cousin and husband of Fāṭima, the Prophet's daughter. 'Alī became the fourth caliph following Muḥammad's death and first Shī'ī imam.

'ālima: learned woman, particularly in religious sciences.

'āmma: the common, ordinary people; but also 'āmm in the sense of ‘public’ as opposed to ‘private’, khāṣṣa (q.v.).

'āshūrā': Shī'ī day of atonement on 10 Muḥarram, commemorating the martyrdom of the imam al-Ḥusayn.

awliyā': lit. ‘friends’, usually referring to the Ismā'īlī devotees.

Ayyūbids: dynasty that ruled Egypt immediately after the demise of the Fāṭimids until 660/1260.

bāb: lit. gate, door; the highest rank after the imam in Fāṭimid Ismā'īlī da'wa hierarchy, often equivalent to dā'ī al-du'āt (q.v.).

bāligh: legal term to indicate maturity and legal competence.

bāṭin: esoteric meaning behind the exoteric wording of sacred texts and religious laws. Bāṭinis or Bāṭiniyya are those people, mostly Shī'ī, who uphold this belief.

batūl: pure, virgin. An adjective particularly used for Fāṭima, the Prophet's daughter, and for Mary, the mother of Jesus.