A "Shi'i" describes something or someone related to Shia Islam, one of the two main branches of Islam. It can mean a Shi'i Muslim or practices, beliefs, or communities of Shia tradition.
Momen, Moojan, An Introduction to Shi'i Islam, Yale University Press, 1985, p.123 *The growth of the Akhbari School which preached that only the Quran, hadith are to be bases for verdicts, rejecting the use of reasoning. Source: Internet
Momen, Moojan, Introduction to Shi'i Islam, Yale University Press, 1985, p.174. Source: Internet
He was tolerant towards Shi'i, but toward the Umayyad community he was not so just. Source: Internet
Supporters of the Bábís paint their struggle as basically defensive in nature; Shi'i writers on the other hand point to this period as proof of the subversive nature of Bábísm. Source: Internet