Where does “vosoir” come from?

vosoir (Old French) comes from Vulgar Latin volsorium, from Latin volsus, from Latin volvō, from Proto-Indo-European wēl-.

Ancestry of “vosoir”, step by step

Step	Language	Word	Meaning
1	Vulgar Latin	volsorium	—
2	Latin	volsus	—
3	Latin	volvō	—
4	Proto-Indo-European	wēl-	—

vosoir — Etymology, Origin & Word History | Etymology Explorer