nestvaran

1. unreal; imaginary
   Sve mi je delovalo nestvarno, kao u snu. — Everything seemed unreal to me, like in a dream.
   Živi u nekom nestvarnom svetu. — He lives in some imaginary world.
2. colloq. incredible; amazing
   Pogled sa Avale je nestvaran! — The view from Avala is amazing!
   Na koncertu je bila nestvarna atmosfera. — The atmosphere at the concert was incredible.

Do not confuse with nerealan "unrealistic": nerealna očekivanja means unrealistic expectations.