The ancient Slavic name Voiak originates from the root -voj-, which means 'warrior, to fight'. This name is similar to other names such as Voilo, Voïn, Voyan, Voya, Vojko, Budivoy, Dobrovoy, which have been preserved among Serbs, Croats, and Bulgarians from ancient times to the present day. Poles, especially the Pomeranians, have recorded it several times in the surname Wojak. For instance, in 1394, it was noted: "Nicolaus dictus Voyak"; in the years 1470-1480: "Vojakowa villa; quam Wojak miles...". Ukrainians have also retained this name basis in the surname Voiak. For example, in 1770, documents recorded Fedor Voiak from Mukachevo, and in 1720 — Jo. Vojak from the village of Yasinnya.
