Where does “isosisko” come from?
isosisko (Finnish) comes from Finnish Sisko, from Finnish sisar, from Proto-Finnic sesar, from Proto-Balto-Slavic swésō, from Proto-Indo-European swésōr, from Proto-Indo-European su-h₁ésh₂-ōr, from Proto-Indo-European h₁ésh₂r̥ — blood.
isosisko (Finnish): big sister
Ancestry of “isosisko”, step by step