An Etymological Dictionary of the German Language/Annotated/Engel
Engel, masculine, from the equivalent Middle High German ęngel, Old High German ęngil, angil, masculine, ‘angel’; corresponding to Old Saxon ęngil, Dutch engel, Anglo-Saxon ęngel (but English angel is borrowed from the Old French angele), Old Icelandic engell, Gothic aggilus, masculine, ‘angel.’ The cognates which are diffused throughout Teutonic are borrowed from the ecclesiastical Latin angelus, or more probably from Greek ἄγγελος, ‘angel.’ How they were borrowed cannot, it is true, be discovered with any certainty (compare Teufel).