Where does “Wac” come from?
Wac (Polish) comes from Polish Wacław, from Czech Václav, from Old Czech Venceslav, from Proto-Slavic *Vęťeslàvъ, from Proto-Slavic slàva, from Proto-Indo-European ḱlew-, from Proto-Indo-European ḱel- — to cover; to incline.
Ancestry of “Wac”, step by step