Where does “Дација” come from?

Дација (Serbo-Croatian) comes from Latin Dacia, from Ancient Greek Δάοι.

Ancestry of “Дација”, step by step

Step	Language	Word	Meaning
1	Latin	Dacia	Denmark; Dacia; greater Romania
2	Ancient Greek	Δάοι	—

Дација — Etymology, Origin & Word History | Etymology Explorer