mid-13c., from O.Fr. espier "to spy," espie "a spy," probably from Frankish *spehon, from P.Gmc. *spekh- (cf. O.H.G. *spehon "to look out for, scout, spy," Ger. spähen "to spy," M.Du. spien), the Gmc. survivals of the productive PIE root *spek- "to look" (see
scope (1)).