Where does “storesøster” come from?
storesøster (Norwegian Bokmål) comes from Norwegian Bokmål søster, 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.
storesøster (Norwegian Bokmål): big sister
Ancestry of “storesøster”, step by step