Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Portuguese sistema
Ancient Greek σύστημα (derived)
Latin systēma (derived)

English system (cognate)
Portuguese ecossistema (affix)
Portuguese sistémico (affix)
Portuguese fotossistema (prefix)
Portuguese agrossistema (affix)
Portuguese antissistema (affix)
Portuguese criptossistema (affix)