Where does “U” come from?

U (English) comes from Tibetan དབུས — middle, centre; Clipping of དབུས་གཙང.

Ancestry of “U”, step by step

Step	Language	Word	Meaning
1	Tibetan	དབུས	middle, centre; Clipping of དབུས་གཙང

U — Etymology, Origin & Word History | Etymology Explorer