Where does “Zacynthius” come from?

Zacynthius (Latin) comes from Ancient Greek Ζακύνθιος, from Ancient Greek -ῐος, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “Zacynthius”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Ζακύνθιος	pertaining to Zakynthos
2	Ancient Greek	-ῐος	belonging to; of”, “belonging to”, “pertaining to
3	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 Ζακύνθιος →