Word Origin & History
early 13c., "to depart, make off;" early 14c., "to turn aside, deviate from a straight course," probably from O.E. sweorfan "to rub, scour, file" (but sense development is difficult to trace), from P.Gmc. *swerbanan (cf O.N. sverfa "to scour, file," O.S. swebran "to wipe off"), from PIE base *swerbh-.
Cognate words in other Germanic languages (cf. O.Fris. swerva "to creep," M.Du. swerven "to rove, stray") suggests the sense of "go off, turn aside" may have existed in O.E., though unrecorded. The noun is recorded from 1741.