Where does “móðursystir” come from?
móðursystir (Icelandic) comes from Icelandic 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.
móðursystir (Icelandic): maternal aunt
Ancestry of “móðursystir”, step by step