nemir

1. anxiety; unease
   Osećam neki nemir pred ispit. — I feel a kind of unease before the exam.
2. (usually plural) unrest; riots
   U gradu su izbili ulični nemiri. — Street riots broke out in the city.
3. (of behaviour) restlessness
   Učiteljica se žali na nemir dece na času. — The teacher complains about the children's restlessness in class.

In the sense "riots" it is usually plural: nemiri.