Where does “tuŵanthu” come from?

tuŵanthu (Tumbuka) comes from Tumbuka tu-, from Proto-Bantu *tʊ̀-.

Ancestry of “tuŵanthu”, step by step

Step	Language	Word	Meaning
1	Tumbuka	tu-	Class 13 noun prefix
2	Proto-Bantu	*tʊ̀-	—