prazniti

1. (+ acc.) to empty
   Ko danas prazni mašinu za sudove? — Who's emptying the dishwasher today?
   Radnici su satima praznili kamion. — The workers spent hours unloading the truck.
2. (prazniti se) to empty; to run down
   Baterija mi se prazni za pola dana. — My battery runs down in half a day.
   Posle ponoći se ulice brzo prazne. — After midnight the streets empty quickly.
3. (prazniti se, of emotions) to vent; to let off steam
   Posle posla se prazni u teretani. — After work he lets off steam at the gym.

The perfective is isprazniti.