Sayyid (also spelled "Seyd", "Syed", "Sayed", "Sayyed", "Saiyid", "Seyed" and "Seyyed") (pronounced [ˈsæjjɪd], or [ˈsæjjed], Arabic: سيد‎; meaning Mister) (plural Sadah Arabic: سادة‎, Sāda(h)) is an honorific title denoting males accepted as descendants of the Islamic prophet Muhammad through his grandsons, Hasan ibn Ali and Husayn ibn Ali, sons of Muhammad's daughter Fatimah and his son-in-law Ali (Ali ibn Abi Talib). Conventionally, descent is patrilineal.