bludnica

1. formal derog. harlot; whore
   U Bibliji se pominje bludnica koja se pokajala. — The Bible mentions a harlot who repented.
2. dated derog. slut; loose woman
   Seljani su je zvali bludnicom samo zato što je bila razvedena. — The villagers called her a loose woman just because she was divorced.

The word is bookish and sounds biblical or old-fashioned; everyday speech uses cruder synonyms.