Where does “uštimati” come from?

uštimati (Serbo-Croatian) comes from Serbo-Croatian u- — in; in-.

uštimati (Serbo-Croatian): to tune, set up, adjust

Definitions

Step	Language	Word	Meaning
1	Serbo-Croatian	u-	in; in-

uštimati — Etymology, Origin & Word History | Etymology Explorer