Where does “百日” come from?

百日 (Japanese) comes from Japanese 日, from Old Japanese 日, from Proto-Japonic *pi — day, sun.

百日 (Japanese): one hundred days

Definitions

  1. one hundred days

Ancestry of “百日”, step by step

百日 traces back through two separate lines of ancestry.

via Japanese 日

StepLanguageWordMeaning
1Japanese日Sunday
2Old Japanese日the sun; sunlight, sunshine; daytime, daylight
3Proto-Japonic*piday, sun

via Japanese 百

StepLanguageWordMeaning
1Japanese百hundred; a very many, lots, a lot; one hundred...
2Middle Chinese百—
Every word from Proto-Japonic *pi →Every word from Old Japanese 日 →Every word from Japanese 日 →