The ancient Slavic name Boiko is still preserved among the southern Slavs. Opinions regarding the origin of this name vary. S. Ilchev classifies the name Boiko as a diminutive formation from the base name Boyo, which in turn is seen as a wishing name derived from the verb "to fear," with the original meaning of "may all fear him!", "may he instill fear!", or "may he be strong in battle!" M. Shymundich considers the modern name Boiko to be derived from Bojan, while Bojan itself comes from the Avar word Bajan – 'leader of the horde.' Alongside this, he, like Serbian researcher M. Grkovich, notes that the contemporary Croatian name Boiko and the Serbian Boiko are now associated with Serbian and Croatian names of Slavic origin, such as Bohdan, Bohomir, Borisav, Bozidar, Slobodan, etc. Elsewhere, explaining the etymology of the name Boyslav, M. Shymundich concludes that the name Boiko originates from the noun boj, meaning 'battle,' or from the verb bojevati - 'to fight.' In the Eastern Slavs, including Ukrainians, the lexeme Boiko is currently used only as a surname and as an ethnonym. For example, in 1661, Bojko Fedor is mentioned - in the village of Ruska (Belay 188); in 1672 - Bojko Szimmyon - in the village of Rakhiv (Belay 181); in 1678 - Bojko Ivan - in the village of Kob. Polyana (Belay 159). Although records from the 17th century from Transcarpathian Hutsul area and Romanian Maramureș contain several anthroponymic names in which the lexeme Boiko can be qualified as a proper personal name. For instance, a record from 1672-1696: Birlas Bojko - in the village of V. Bychki (Belay 129); in 1680: Bojko Koszej - in the village of Ruska Polyana (Belay 180). It is also worth mentioning a record from 1489: "a village named Boikivtsi" - in the town of Suceava and the patronymic surname of a Cossack from the Uman regiment in 1649 - Basyly Boichenko.
