sužavati

1. (+ acc.) to narrow; to narrow down
   Policija polako sužava krug osumnjičenih. — The police are gradually narrowing down the list of suspects.
   Novi zakon sužava prava zakupaca. — The new law narrows tenants' rights.
2. (sužavati se) to narrow; to get narrower
   Put se posle mosta sužava. — The road narrows after the bridge.
   Zenice se sužavaju na jakom svetlu. — Pupils contract in bright light.

The perfective is suziti.