Where does “فَلَقَة” come from?

فَلَقَة (Arabic) comes from Ancient Greek φάλαγξ, from Proto-Indo-European bʰelǵ- — to balk, beam.

Ancestry of “فَلَقَة”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	φάλαγξ	line of battle, battle-array; ranks of an army;...
2	Proto-Indo-European	bʰelǵ-	to balk, beam