Where does “systeri” come from?
systeri (Finnish) comes from Swedish syster, from Old Swedish systir, from Old Norse systir, from Proto-Norse ᛊᚹᛖᛊᛏᚨᚱ, from Proto-Germanic swestēr, from Proto-Indo-European swésōr, from Proto-Indo-European su-h₁ésh₂-ōr, from Proto-Indo-European h₁ésh₂r̥ — blood.
systeri (Finnish): sister, sissy
Ancestry of “systeri”, step by step