Where does “наший” come from?

наший (Ukrainian) comes from Ukrainian наш, from Proto-Slavic našь, from Proto-Balto-Slavic nōsjas, from Proto-Indo-European nōsyos, from Proto-Indo-European nōs-.

Ancestry of “наший”, step by step

StepLanguageWordMeaning
1Ukrainianнашour, ours; ethnically Ukrainian
2Proto-Slavicnašьour
3Proto-Balto-Slavicnōsjas—
4Proto-Indo-Europeannōsyos—
5Proto-Indo-Europeannōs-—
Every word from Proto-Indo-European nōs- →Every word from Proto-Indo-European nōsyos →Every word from Proto-Balto-Slavic nōsjas →