An Etymological Dictionary of the German Language/scheel
scheel, adj., ‘oblique, awry,’ from MidHG. schël, schëlch (gen. schëlhes, schëlwes), OHG. scëlah (gen. scëlhes, scëlawes), adj., ‘awry, squinting, athwart, oblique, crooked’; comp. Du. scheel, AS. sčeolh, OIc. skjalgr, ‘awry, squinting’ (Goth. *skilhwa-, or rather *skilwa-, *skilga-, is by chance not recorded). Pre-Teut. *skelko-, skëlqo-, must be assumed; hence Gr. σκολιός, ‘aslant, awry,’ is not quite adequate to explain phonetically the Teut. forms; perhaps both the Teut. and Gr. terms are based on a root skel.