Where does “فارسی” come from?
فارسی (Classical Persian) comes from Arabic فَارْسِي, from Persian پارسی, from Middle Persian pʾlsyk', from Old Persian 𐎱𐎠𐎼𐎿, from Proto-Iranian párcuš, from Proto-Indo-Iranian párćuš, from Proto-Indo-European pérḱus — chest; rib.