Deriva translates to "adrift" or "drifting". It's a less common word in everyday conversation, making it stand out in the lyrics.
In the song, the singer uses the phrase "Um barco à deriva, num mar de amor" (A boat adrift, in a sea of love). This metaphor beautifully conveys a feeling of being lost and carried away by intense emotions, specifically love, without control or direction. It paints a vivid picture of passionate surrender.
"Pecado Original" is about a love that feels impossible to resist. The singer says he's crazy for someone, and being apart from them feels like torture that leaves him adrift, like a boat lost at sea.
When the phone finally rings and he hears their voice, that longing turns into something almost uncontrollable, a wild, insatiable desire he can't talk himself out of.
He calls the person a goddess and an Eve, and their attraction an "original sin", a nod to the Bible's Adam and Eve story. Nothing else in the world matters once they're together; the chorus keeps circling back to that one craving.