Where does “九” come from?

九 (Korean) comes from Middle Chinese 九, from Old Chinese 九, from Proto-Sino-Tibetan d/s-kəw — nine.

Ancestry of “九”, step by step

StepLanguageWordMeaning
1Middle Chinese九—
2Old Chinese九—
3Proto-Sino-Tibetand/s-kəwnine
Every word from Proto-Sino-Tibetan d/s-kəw →Every word from Old Chinese 九 →Every word from Middle Chinese 九 →