kako se zove

1. colloq. (while searching for a word) what's-it-called; um; er
   Dodaj mi onaj, kako se zove, šrafciger. — Pass me that, what's-it-called, screwdriver.
   Bili smo u onom, kako se zove, tržnom centru. — We were at that, um, shopping centre.

2. (asking a name) what's his (her) name?; what's it called?
   Kako se zove tvoj brat? — What's your brother's name?
   Kako se zove ova ulica? — What's this street called?

As a filler it is not a real question and needs no answer.