The Zaydis are the followers of Zayd al-Shahid, the son of Imam al-Sajjad. Zayd rebelled in 121/737 against the Umayyad caliph Hisham 'Abd al-Malik and a group paid allegiance to him. A battle ensued in Kufa between Zayd and the army of the caliph in which Zayd was killed.
ZAYDISM
Meaning of ZAYDISM in English
Advanced Islamic English dictionary. Расширенный исламский словарь английского языка. 2012