nastavnica

1. teacher; schoolteacher
   Nastavnica srpskog nam je dala mnogo domaćeg. — Our Serbian teacher gave us a lot of homework.
   Moja mama radi kao nastavnica hemije. — My mum works as a chemistry teacher.

For grades 1–4 people usually say "učiteljica", for grades 5–8 "nastavnica", and in secondary school and university "profesorka".