Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Portuguese -o
← Latin -um (inherited)
← Latin -ō (inherited)
← Old Portuguese -o (inherited)
← Old Portuguese -o (inherited)

→ Portuguese valáquio (affix)
→ Portuguese polissílabo (affix)
→ Portuguese aglosso (affix)
→ Portuguese aperspectivo (affix)
→ Portuguese sereio (affix)