ukočiti

1. (ukočiti se, of a body part) to get stiff; to go numb
   Ukočio mi se vrat od klime. — My neck got stiff from the air conditioning.
   Posle dugog sedenja ukočila su mi se leđa. — After sitting for a long time my back went stiff.
2. (ukočiti se, from fear or shock) to freeze; to go rigid
   Kad je video psa, dete se ukočilo od straha. — When he saw the dog, the child froze with fear.
3. (+ acc.) to paralyse; to stiffen
   Hladnoća mu je ukočila prste. — The cold stiffened his fingers.
4. colloq. (of a driver, driving) to brake; to slam on the brakes
   Naglo je ukočio da ne udari psa. — He braked hard so as not to hit the dog.
   Vozač je ukočio ispred pešačkog prelaza. — The driver braked in front of the pedestrian crossing.

Mostly used reflexively: ukočiti se. In the sense 'to brake' it is used without se.