An Etymological Dictionary of the German Language/Annotated/hehlen

hehlen, verb from the equivalent Middle High German hëln, Old High German hëlan, ‘to keep secret, conceal,’ Anglo-Saxon hëlan, English to heal, ‘to cover, conceal,’ Dutch helen, ‘to conceal.’ Root hē̆l, from pre-Teutonic kē̆l (Sanscrit *çal), in the sense of ‘concealing cover’; see further under Halle, Hehl, Hölle, Hülle, Hülse, as well as hohl, Höhle, and Helm. The Aryan root is attested by Latin cêlare (ê as in Gothic *hêlei, which is indicated by Middle High German hœle, feminine, mentioned under Hehl), occulo, Greek root καλ in καλύπτω, ‘I cover,’ καλύβη, ‘hut,’ Old Irish celim, ‘I hide.’