Where does “シー” come from?

シー (Japanese) comes from English cee, from Middle English cee, from Old French sei, from Latin sēdēs, from Latin sedeō, from Proto-Italic sedēō, from Proto-Indo-European sḗd- — to sit.

シー (Japanese): The name of the Latin-script letter C; the sea

Definitions

The name of the Latin-script letter C; the sea

Ancestry of “シー”, step by step

Step	Language	Word	Meaning
1	English	cee	The name of the Latin-script letter C; Something...
2	Middle English	cee	Alternative form of see
3	Old French	sei	—
4	Latin	sēdēs	seat, chair
5	Latin	sedeō	to sit, to be seated
6	Proto-Italic	sedēō	sit, be sitting, be seated
7	Proto-Indo-European	sḗd-	to sit

Every word from Proto-Indo-European sḗd- →Every word from Proto-Italic sedēō →Every word from Latin sedeō →