Where does “天皇誕生日” come from?

天皇誕生日 (Japanese) comes from Japanese 誕生日, from Japanese 日, from Old Japanese 日, from Proto-Japonic *pi — day, sun.

天皇誕生日 (Japanese): a national holiday in Japan on the birthday of the 今上天皇, currently February 23

Definitions

  1. a national holiday in Japan on the birthday of the 今上天皇, currently February 23

Ancestry of “天皇誕生日”, step by step

天皇誕生日 traces back through two separate lines of ancestry.

via Japanese 誕生日

StepLanguageWordMeaning
1Japanese誕生日a birthday
2Japanese日Sunday
3Old Japanese日the sun; sunlight, sunshine; daytime, daylight
4Proto-Japonic*piday, sun

via Japanese 天皇

StepLanguageWordMeaning
1Japanese天皇an Emperor or Empress of Japan; an emperor,...
2Old Japanese天皇a sovereign who governs a region; a term of...
3Old Japanese君emperor; lord, master → sovereign

Words derived from “天皇誕生日”

Every word from Proto-Japonic *pi →Every word from Old Japanese 日 →Every word from Japanese 日 →