پل (Classical Persian) comes from Middle Persian 𐭯𐭥𐭧𐭫𐭩, from Proto-Indo-Iranian pártuš, from Proto-Indo-European pértus, from Proto-Indo-European per-, from Proto-Indo-European pr̥tós — passed , crossed.
Ancestry of “پل”, step by step
پل traces back through two separate lines of ancestry.