From Middle English tor, tore, toor, from Old Norse tor- ("hard, difficult, wrong, bad"), from Proto-Germanic *tuz- ("hard, difficult, wrong, bad"), from Proto-Indo-European *dus- ("bad, ill, difficult"), from Proto-Indo-European *dēwǝ- ("to fail, be behind, be lacking"). Cognate with Old High German zur- ("mis-"), Gothic 𐍄𐌿𐌶- ("hard, difficult"), Ancient Greek δυσ- ("bad, ill, difficult"). More at dys-.