pritvoriti

1. (of police, a court) to detain; to take into custody
   Policija je pritvorila osumnjičenog na 48 sati. — The police detained the suspect for 48 hours.
   Sud je odlučio da ga pritvori do suđenja. — The court decided to hold him in custody until trial.
2. (of a door, window) to close partly; to push to
   Pritvori vrata, promaja je. — Push the door to, there's a draught.
   Pritvorila je prozor i legla da spava. — She half-closed the window and went to bed.

The imperfective is pritvarati; the noun pritvor means "pre-trial detention".