ludača

1. colloq. derog. crazy woman; silly woman
   Ta ludača je opet vikala na komšije. — That crazy woman was yelling at the neighbors again.
2. colloq. affect. (as a playful address) silly thing; crazy girl
   Ma ludačo jedna, nasmejala si me do suza! — You crazy girl, you made me laugh till I cried!

The masculine counterpart is ludak.