Where does “Koh” come from?

Koh (English) comes from Korean 고, from Chinese 古, from Proto-Sino-Tibetan r-ga — old.

Ancestry of “Koh”, step by step

StepLanguageWordMeaning
1Korean고and then; and; -ing
2Chinese古—
3Proto-Sino-Tibetanr-gaold
Every word from Proto-Sino-Tibetan r-ga →Every word from Chinese 古 →Every word from Korean 고 →