Where does “Ü-Tsang” come from?

Ü-Tsang (English) comes from Tibetan དབུས་གཙང, from Tibetan གཙང, from Proto-Sino-Tibetan (t)s(j)aŋ — clear; pure; clean; clean; pure; clear.

Ancestry of “Ü-Tsang”, step by step

StepLanguageWordMeaning
1Tibetanདབུས་གཙངÜ-Tsang
2Tibetanགཙངclean, pure; See གཙང་བ
3Proto-Sino-Tibetan(t)s(j)aŋclear; pure; clean; clean; pure; clear
Every word from Proto-Sino-Tibetan (t)s(j)aŋ →Every word from Tibetan གཙང →Every word from Tibetan དབུས་གཙང →