ler

1. colloq. (of a gearbox) neutral; neutral gear
   Stavi u ler pre nego što upališ auto. — Put it in neutral before you start the car.
   Nizbrdo je vozio u leru. — He drove downhill in neutral.
2. colloq. (in "u leru") idleness; standstill
   Ceo vikend sam bio u leru. — I was idling all weekend.
   Projekat je već mesec dana u leru. — The project has been at a standstill for a month.
3. colloq. (of an engine) idling; idle
   Motor radi u leru, ali auto ne može da krene. — The engine is idling, but the car won't move.

It is usually used in the phrases "u leru" and "staviti u ler".