Where does “구” come from?

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

구 (Korean): a suffix deriving a causative verb; a colloquial...

Definitions

  1. a suffix deriving a causative verb; a colloquial...

Ancestry of “구”, step by step

구 traces back through two separate lines of ancestry.

via Middle Chinese 九

StepLanguageWordMeaning
1Middle Chinese九—
2Old Chinese九—
3Proto-Sino-Tibetand/s-kəwnine

via Chinese 口

StepLanguageWordMeaning
1Chinese口mouth
2Proto-Sino-Tibetanku(w)mouth
Every word from Proto-Sino-Tibetan d/s-kəw →Every word from Old Chinese 九 →Every word from Middle Chinese 九 →