Where does “styvsyskon” come from?
styvsyskon (Swedish) comes from Swedish syskon, from Old Swedish systkin, from Old Norse systkin, from Old Norse systir, from Proto-Norse ᛊᚹᛖᛊᛏᚨᚱ, from Proto-Germanic swestēr, from Proto-Indo-European swésōr, from Proto-Indo-European su-h₁ésh₂-ōr — blood.
styvsyskon (Swedish): a stepsibling
Ancestry of “styvsyskon”, step by step