scowl (v.) Look up scowl at Dictionary.com
mid-14c., from a Scandinavian source (cf. Norwegian skule "look furtively, squint, look embarrassed," Danish skule "to scowl"). Probably related to Old English sceolh "wry, oblique," Old High German scelah "curved," German scheel "squint-eyed;" from PIE root *sqel- "crooked, curved, bent." Related: Scowled; scowling. The noun is attested from c.1500.