Where does “سپستان” come from?

سپستان (Classical Persian) comes from Persian پستان, from Middle Persian pystʾn', from Proto-Indo-European pstḗn, from Proto-Indo-European ph₂ǵ-sth₂-ḗn, from Proto-Indo-European steh₂- — to stand.

Ancestry of “سپستان”, step by step

سپستان traces back through two separate lines of ancestry.

via Persian پستان

StepLanguageWordMeaning
1Persianپستانbreast
2Middle Persianpystʾn'
3Proto-Indo-Europeanpstḗnbreast, teat
4Proto-Indo-Europeanph₂ǵ-sth₂-ḗn
5Proto-Indo-Europeansteh₂-to stand

via Persian سگ

StepLanguageWordMeaning
1Persianسگdog
2Proto-Iraniancwā́dog
3Proto-Indo-Iranianćwā́dog
4Proto-Indo-Europeanḱwṓdog
Every word from Proto-Indo-European steh₂-Every word from Proto-Indo-European ph₂ǵ-sth₂-ḗnEvery word from Proto-Indo-European pstḗn