An Etymological Dictionary of the German Language/Engel
Engel, m., from the equiv. MidHG. ęngel, OHG. ęngil, angil, m., ‘angel’; corresponding to OSax. ęngil, Du. engel, AS. ęngel (but E. angel is borrowed from the OFr. angele), OIc. engell, Goth. aggilus, m., ‘angel.’ The cognates which are diffused throughout Teut. are borrowed from the ecclesiastical Lat. angelus, or more probably from Gr. ἄγγελος, ‘angel.’ How they were borrowed cannot, it is true, be discovered with any certainty (comp. Teufel).