From Middle Breton buguel, from Proto-Brythonic *bʉgöl, from Proto-Celtic *boukolyos, from Proto-Indo-European *gʷowkólos, from *gʷṓws (“cow”) + *kʷel- (“to revolve, turn around”). Cognates include Cornish bugel (“shepherd”), Welsh bugail (“shepherd”), Irish buachaill (“boy”), Scottish Gaelic buachaille (“herder”), Manx bochilley (“shepherd”) and Ancient Greek βουκόλος (boukólos, “cowherd”).