Where does “објавити” come from?

објавити (Serbo-Croatian) comes from Serbo-Croatian об-, from Proto-Slavic ob, from Proto-Indo-European h₃ebʰi.

Ancestry of “објавити”, step by step

Step	Language	Word	Meaning
1	Serbo-Croatian	об-	around, enclosing, surrounding; around,...
2	Proto-Slavic	ob	around, against
3	Proto-Indo-European	h₃ebʰi	—

објавити — Etymology, Origin & Word History | Etymology Explorer