An Etymological Dictionary of the German Language/Annotated/scheel
scheel, adjective, ‘oblique, awry,’ from Middle High German schël, schëlch (genitive schëlhes, schëlwes), Old High German scëlah (genitive scëlhes, scëlawes), adjective, ‘awry, squinting, athwart, oblique, crooked’; compare Dutch scheel, Anglo-Saxon sčeolh, Old Icelandic skjalgr, ‘awry, squinting’ (Gothic *skilhwa-, or rather *skilwa-, *skilga-, is by chance not recorded). Pre-Teutonic *skelko-, skëlqo-, must be assumed; hence Greek σκολιός, ‘aslant, awry,’ is not quite adequate to explain phonetically the Teutonic forms; perhaps both the Teutonic and Greek terms are based on a root skel.