ukrutiti

1. (ukrutiti se; of the body) to stiffen; to go stiff
   Prsti su mi se ukrutili od hladnoće. — My fingers went stiff from the cold.
   Posle dugog leta vrat mi se potpuno ukrutio. — After the long flight my neck got completely stiff.
2. (ukrutiti se; of a person) to tense up; to freeze up
   Čim je ugledao kameru, ukrutio se i zaboravio tekst. — As soon as he saw the camera, he tensed up and forgot his lines.
3. (+ acc.) to stiffen; to make rigid
   Malo škroba će ukrutiti kragnu. — A little starch will stiffen the collar.

Most often used reflexively: ukrutiti se.