Where does “pex” come from?

pex (Old French) comes from Latin pālus, from Proto-Italic pākslos, from Proto-Indo-European peh₂ǵ-slos, from Proto-Indo-European peh₂ǵ- — to attach.

Ancestry of “pex”, step by step

Step	Language	Word	Meaning
1	Latin	pālus	—
2	Proto-Italic	pākslos	—
3	Proto-Indo-European	peh₂ǵ-slos	—
4	Proto-Indo-European	peh₂ǵ-	to attach

pex — Etymology, Origin & Word History | Etymology Explorer