An Etymological Dictionary of the German Language/Annotated/welk
welk, adjective, ‘withered, faded,’ from Middle High German and Old High German wëlc (wëlch), ‘moist, mild, lukewarm, faded’; peculiar to High German; connected with Middle English welken, English to welk, and Wolke. The primary meaning of the Teutonic root welk, from Aryan welg, is ‘to be moist,’ as is indicated also by Old Slovenian vlaga, ‘moistness,’ vlûgûkû, ‘moist,’ Lithuanian vìlgyti, ‘to moisten,’ Lettic wélgans, wálgans, ‘moist,’ unless these are more closely allied to Anglo-Saxon wlacu, wlœc, ‘moist.’ From a form *walki, connected with Old High German wëlk, French gauche, ‘left,’ is usually derived.