Where does “した” come from?

した (Old Japanese) comes from Translingual − — A long signal, used to form Morse code text, together with. (a short signal).

Ancestry of “した”, step by step

した traces back through two separate lines of ancestry.

via Translingual

StepLanguageWordMeaning
1TranslingualA long signal, used to form Morse code text, together with. (a short signal)

via Proto-Japonic sita

StepLanguageWordMeaning
1Proto-Japonicsitadown

Words derived from “した

Every word from Translingual
した — Etymology, Origin & Word History | Etymology Explorer