luđakinja

1. colloq. derog. crazy woman; madwoman
   Vozi kao luđakinja, bojim se da sednem s njom. — She drives like a madwoman, I'm scared to ride with her.
   Ta luđakinja je opet vikala na komšije. — That crazy woman was yelling at the neighbours again.
2. dated derog. madwoman; lunatic
   U selu su je svi smatrali luđakinjom. — Everyone in the village considered her a madwoman.

The masculine form is luđak.