All around the world, Костач (Костач , Kostach ) is an extremely rare unknown gender given name. Much more prevalently, Костач is the last name as well as the forename.
Kostač
Михаил, Андрей, Надежда, and Владимир
, Kostach 
) is an extremely rare unknown gender given name. Much more prevalently, Костач is the last name as well as the forename.