Where does “fiastre” come from?
fiastre (Friulian) comes from Friulian fiastri, from Late Latin filiaster, from Latin fīlius, from Old Latin fīlios, from Proto-Indo-European dʰeh₁y-li-os, from Proto-Indo-European dʰeh₁(y)- — to suckle, nurse.
fiastre (Friulian): stepdaughter
Ancestry of “fiastre”, step by step