smrznuti

1. (smrznuti se) to freeze
   Jezero se smrzlo preko noći. — The lake froze overnight.
   Cevi su se smrzle zbog minusa. — The pipes froze because of the frost.
2. (smrznuti se, of a person) to freeze; to get very cold
   Smrzla sam se dok sam čekala autobus. — I froze while waiting for the bus.
3. to freeze
   Mraz je smrznuo sve cveće u bašti. — The frost froze all the flowers in the garden.
4. (smrznuti se, from fear) to freeze; to be petrified
   Kad sam čuo korake iza sebe, smrzao sam se. — When I heard footsteps behind me, I froze.

For putting food in the freezer, zamrznuti is usually used.