An Etymological Dictionary of the German Language/Annotated/weh
weh, interjection, ‘woe! alas!’ from the equivalent Middle High German and Old High German wê; corresponding to Gothic wai, Anglo-Saxon wâ, English woe. From the Teutonic interjection wai is derived the equivalent Italian and Spanish guai (French ouais). As in the case of Latin vae (Greek οἷ), weh is to be regarded as an instinctive sound. The substantive Weh, neuter, ‘plaint, misery, woe,’ seems to be based on the interjection; compare Old Saxon, Old High German, and Middle High German wê (genitive wêwes), and Old High German wêwo, masculine, wêva, feminine, ‘woe, pain, sorrow,’ and the borrowed Italian guajo, ‘sorrow.’ See weinen and wenig.