 His son Jonas Kęsgailaitis, mentioned in written sources in Latin as "Johannes Kyensgalowicz", was a bearer of the name as a patronymic, which subsequently evolved into a family name.Its Polonized form "Kieżgajło" is most common in Polish historiography over other variants, such as "Kezigal", "Kieżgajłła", "Gezgajło", "Kiezgajło", "Kieżgajłło", "Kierżgajłło", "Kieżgałło" and "Kieżgało".