Where does “Žarko” come from?

Žarko (Serbo-Croatian) comes from Serbo-Croatian žar, from Ottoman Turkish زار, from Persian زار, from Arabic زَهْر, from Ancient Greek τέσσερα, from Ancient Greek τέσσᾰρᾰ, from Ancient Greek τέσσᾰρες, from Proto-Hellenic kʷétwores — and.

Ancestry of “Žarko”, step by step

Step	Language	Word	Meaning
1	Serbo-Croatian	žar	fervor, ardor; ember
2	Ottoman Turkish	زار	membrane, film, skin, wrap; die
3	Persian	زار	groan; lament; die
4	Arabic	زَهْر	cube, die; dice; the dice
5	Ancient Greek	τέσσερα	four
6	Ancient Greek	τέσσᾰρᾰ	four
7	Ancient Greek	τέσσᾰρες	four
8	Proto-Hellenic	kʷétwores	cardinal...
9	Proto-Indo-European	kʷetwóres	four
10	Proto-Indo-European	kʷe-	and

Every word from Proto-Indo-European kʷe- →Every word from Proto-Indo-European kʷetwóres →Every word from Proto-Hellenic kʷétwores →