Etymology Borrowed from Scots scunner, skunner, from Old Scots skunnyr, skowner (“to shrink back; flinch”), from Middle English skoneren (“to feel sick or disgusted”), of uncertain origin. Perhaps from a frequentative of shun. If so, etymologically shun + -er (frequentative suffix). Compare also Middle English scurnen (“to flinch”), English scare, English scorn.
But maybe she'd just got scunnered with Glasgow, fucked off to try her luck someplace else.2022, Liam McIlvanney, The Heretic, page 123:
scunner
noun
Etymology Borrowed from Scots scunner, skunner, from Old Scots skunnyr, skowner (“to shrink back; flinch”), from Middle English skoneren (“to feel sick or disgusted”), of uncertain origin. Perhaps from a frequentative of shun. If so, etymologically shun + -er (frequentative suffix). Compare also Middle English scurnen (“to flinch”), English scare, English scorn.