Where does “Hroth₂os” come from?

Hroth₂os (Proto-Indo-European) comes from Proto-Indo-European Hret- — to roll; wheel; to run, roll.

Ancestry of “Hroth₂os”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	Hret-	to roll; wheel; to run, roll

Hroth₂os — Etymology, Origin & Word History | Etymology Explorer