Where does “сирꙑи” come from?

сирꙑи (Old East Slavic) comes from Proto-Slavic sirъ, from Proto-Indo-European śeiros, from Proto-Indo-European ḱei-ro-.

Ancestry of “сирꙑи”, step by step

StepLanguageWordMeaning
1Proto-Slavicsirъorphaned
2Proto-Indo-Europeanśeiros—
3Proto-Indo-Europeanḱei-ro-—
Every word from Proto-Indo-European ḱei-ro- →Every word from Proto-Indo-European śeiros →Every word from Proto-Slavic sirъ →
сирꙑи — Etymology, Origin & Word History | Etymology Explorer