An Etymological Dictionary of the German Language/Annotated/kerben
kerben, verb ‘to notch,’ from the equivalent Middle High German kërben (with a strong participle gekurben in Lower Rhenish); an originally strong verb with the graded forms kërfan, karf, kurbum, korban (compare Anglo-Saxon čeorfan, English to carve, Dutch kerven); the final f of the stem kerf is attested by the Middle High German kërve, a variant of kërbe; Gothic *kaírfan is wanting. The root kerf is found also in Greek γράφω, ‘to write,’ properly ‘to cut in, scratch’ (compare High German reißen with English to write), which with Teutonic kerf points to a Sanscrit root *gṛph.