Where does “Caio” come from?

Caio (Portuguese) comes from Latin Cāius, from Latin -ius, from Proto-Italic -jōs, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “Caio”, step by step

StepLanguageWordMeaning
1LatinCāius — famously held by
2Latin-iusforming adjectives from nouns; nominative neuter...
3Proto-Italic-jōsForms comparative adjectives
4Proto-Indo-European-yósCreates adjectives from noun or verb stems
Every word from Proto-Indo-European -yós →Every word from Latin -ius →Every word from Proto-Italic -jōs →