Word Origin & History
O.E., "an Arab" (in Gk. and Roman translations), also, mid-13c., generally, "non-Christian, heathen, pagan," from O.Fr. saracin, from L.L. saracenus, from Gk. sarakenos, usually said to be from Arabic Sharquiyin, accusative plural of sharqiy "eastern," from sharq "east, sunrise," but this is not certain.
In Medieval times the name was associated with that of Biblical Sarah
"Peple þat cleped hem self Saracenys, as þogh þey were i-come of Sarra" [John of Trevisa, transl. Higdon's Polychronicon, 1387]
The name Greeks and Romans gave to the nomads of the Syrian and Arabian deserts. Specific sense of "Middle Eastern Muslim" is from the Crusades.