Syed (also spelled “Seyd”, “Sayyid”, “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).

In the Ottoman Empire, Muhammad’s descendants formed a kind of nobility with the privilege of wearing green turbans.

Source and photo credits: WikiPedia