An Etymological Dictionary of the German Language/Bischof
Bischof, m., ‘bishop,’ from the equiv. MidHG. bischof (v), OHG. biscof (to which Bistum is related); Du. bisschop, AS. bisceop, E. bishop, with the same meaning. In Goth. with a closer adherence to the primit. form (ἐπίσκοπος) aípiskaúpus. This widely diffused word was probably adopted, like the Arianism of the Goths (comp. Kirche), from the Greeks without passing through Romance. The Lat.-Rom. origin is indeed supported by the initial b as well as the loss of the original e at the beginning; comp. Ital. vescovo, OFr. vesque (also evesque, ModFr. évêque, and OIr. epscop). Comp. further OSlov. jepĭskopŭ.