Where does “[[siu]], [[si]]” come from?

[[siu]], [[si]] (Old High German) comes from Proto-West Germanic [[*si(j)u]], [[*sī]], from Proto-Germanic sī, from Proto-Indo-European sih₂, from Proto-Indo-European -ih₂, from Proto-Indo-European -h₂ — Creates collective nouns, which refer to groups...

Ancestry of “[[siu]], [[si]]”, step by step

StepLanguageWordMeaning
1Proto-West Germanic[[*si(j)u]], [[*sī]]
2Proto-Germanic
3Proto-Indo-Europeansih₂she
4Proto-Indo-European-ih₂Feminizes athematic nominal stems
5Proto-Indo-European-h₂Creates collective nouns, which refer to groups...
Every word from Proto-Indo-European -h₂Every word from Proto-Indo-European -ih₂Every word from Proto-Indo-European sih₂