Where does “зо̑р” come from?

зо̑р (Serbo-Croatian) comes from Ottoman Turkish زور, from Persian زور, from Parthian zʿwr.

Ancestry of “зо̑р”, step by step

Step	Language	Word	Meaning
1	Ottoman Turkish	زور	hard, difficult, exhausting; force, strength,...
2	Persian	زور	libation; force, strength, power, might;...
3	Parthian	zʿwr	—

зо̑р — Etymology, Origin & Word History | Etymology Explorer