Feitiço translates directly to "spell" or "charm". It's a central and evocative word that immediately brings to mind magic and enchantment, making it very intriguing.
In the context of the song, the phrase "I put a spell on you" is the core theme, and feitiço is the Portuguese equivalent. It captures the intense, almost supernatural hold the singer feels she has over someone, making it a powerful and memorable word for learners.