Definition of fash in English:

fash

verb

fash oneself
Scottish
  • Feel upset or worried:

    ‘she'll be coming soon, don't fash yourself’
    ‘it's only a wee bit of broken glass, dinna fash!’

Origin

Mid 16th century: from early modern French fascher, based on Latin fastus disdain, scornful contempt.

Pronunciation:

fash

/faʃ/