Where does “Pelagio” come from?

Pelagio (Italian) comes from Latin Pelagius, from Ancient Greek πελάγιος, from Ancient Greek -ῐος, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “Pelagio”, step by step

Step	Language	Word	Meaning
1	Latin	Pelagius	pelagian, pelagic (of or relating to the open sea)
2	Ancient Greek	πελάγιος	of the sea
3	Ancient Greek	-ῐος	belonging to; of”, “belonging to”, “pertaining to
4	Proto-Indo-European	-yós	Creates adjectives from noun or verb stems

Every word from Proto-Indo-European -yós →Every word from Ancient Greek -ῐος →Every word from Ancient Greek πελάγιος →