The Collaborative International Dictionary of English v.0.48:

Shereef \Sher"eef\, Sherif \Sher"if\, n. [Ar. sher[imac]f noble,
   holy, n., a prince.]
   A member of an Arab princely family descended from Mohammed
   through his son-in-law Ali and daughter Fatima. The Grand
   Shereef is the governor of Mecca.
   [1913 Webster]