Where does “Gyatso” come from?

Gyatso (English) comes from Tibetan རྒྱ་མཚོ, from Tibetan རྒྱ, from Proto-Tibeto-Burman r-gya-n.

Ancestry of “Gyatso”, step by step

StepLanguageWordMeaning
1Tibetanརྒྱ་མཚོsea, ocean
2Tibetanརྒྱextent, size, area, width; vastness,...
3Proto-Tibeto-Burmanr-gya-n—
Every word from Proto-Tibeto-Burman r-gya-n →Every word from Tibetan རྒྱ →Every word from Tibetan རྒྱ་མཚོ →