From a parallel form *kurt of the (old) verb kurst (“to be(come) pierced, hollow, torn”), derived with an extra -l (cf. also the dialectal form kursls, from kurst), from Proto-Indo-European *(s)ker- (“to cut off”). The semantic evolution was: “with holes, hollow” > “having ears with holes, mutilated ears” > “not hearing well” > “deaf”. Cognates include Lithuanian kur̃čias, dialectal kur̃las, kur̃tas, Old Church Slavonic крънъ (krŭnŭ, “mutilated (ears, nose)”), Avestan 𐬐𐬀𐬭𐬥𐬀 (karna), Northern Kurdish kerr.