kvaran

1. (of things, devices) defective; damaged
   Kvarnu robu možete vratiti u roku od mesec dana. — You can return defective goods within a month.
2. colloq. derog. (of a person) rotten; sly; corrupt
   Ne verujem mu, on je kvaran čovek. — I don't trust him, he's a rotten person.
3. (of food) spoiled; rotten
   Bacili smo kvarno meso iz frižidera. — We threw the spoiled meat out of the fridge.

In everyday speech pokvaren is much more common.