kočiti

1. (of a vehicle) to brake
   Uvek kočim polako kad je put mokar. — I always brake gently when the road is wet.
   Autobus je kočio pred svakim semaforom. — The bus braked at every traffic light.
2. (of progress, action) to hinder; to hold back; to hamper
   Birokratija koči razvoj malih firmi. — Bureaucracy is holding back the growth of small businesses.
   Strah ga koči da progovori na sastanku. — Fear keeps him from speaking up in meetings.
3. (kočiti se) to stiffen; to go stiff
   Od hladnoće su mi se kočili prsti. — My fingers were going stiff from the cold.

The perfective is zakočiti: Naglo je zakočio means "He braked suddenly".