Where does “Vo” come from?

Vo (Czech) comes from Vietnamese vô, from Vietnamese vụ, from Chinese 務, from Sino-Tibetan *mow.

Ancestry of “Vo”, step by step

Step	Language	Word	Meaning
1	Vietnamese	vô	to enter; to go into; to toast; emphasizing...
2	Vietnamese	vụ	season; case, affair; specialized department...
3	Chinese	務	—
4	Sino-Tibetan	*mow	—