Where does “Borromeo” come from?

Borromeo (Spanish) comes from Italian Borromeo, from Italian Romeo, from Latin romaeus, from Ancient Greek ῥωμαῖος, from Ancient Greek -αῖος, from Ancient Greek -ῐος, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “Borromeo”, step by step

StepLanguageWordMeaning
1ItalianBorromeo
2ItalianRomeoRoman
3LatinromaeusRomaean, Byzantine
4Ancient GreekῥωμαῖοςRoman
5Ancient Greek-αῖοςSuffix added to nouns or adjectives, forming adjectives: pertaining to, belonging to ("of")
6Ancient Greek-ῐοςbelonging to; of”, “belonging to”, “pertaining to
7Proto-Indo-European-yósCreates adjectives from noun or verb stems
Every word from Proto-Indo-European -yós