Anciently, an Arab; later, a Mussulman; in the Middle Ages, the common term among Christians in Europe for a Mohammedan hostile to the crusaders.

1.a member of one of the nomadic Arabic tribes, esp. of the Syrian desert, that harassed the borders of the Roman Empire in that region; a Muslim, esp. one who opposed the crusades; (later) any Arab; 2. relating to Arabs of either of these periods, regions, or types.

(historically) a member of the nomadic people of the Syrian and Arabian deserts at the time of the Roman Empire

Saracen was a 1989 ITV action drama about a private security firm of that name.