Sharīf (Arabic: شريف ) is a traditional Arab tribal title given to those to serve as the protector of the tribe and all tribal assets, property, land, wells etc.
It is used, in the Islamic tradition (both Sunni and Shia), to refer to those claiming descent from Muhammad through Hasan, son of his daughter Fatima Zahra and son-in-law ˤAlī. (Descendants of another son, Husayn, are often referred to as Sayyid.) From 1201, this family held the office of the Sharīf of Makkah and descendants now rule Jordan.
Note: Although it may be tempting to infer an etymological connection with the English term sheriff, the latter term actually comes from the Old English word scīrgerefa, meaning "shire-reeve", being the local reeve (enforcement agent) of the king in the shire (county).