Cicatrizou comes from the verb cicatrizar, meaning "to heal" or "to scar over." It's a vivid and somewhat less common verb in everyday conversation, making it stand out.
In the context of the song, the lyrics state, "Que a ferida não cicatrizou" (That the wound did not heal). This powerful imagery conveys deep emotional pain and longing, suggesting that the singer's heartbreak is still fresh and unresolved, despite the passage of time. It's a poignant way to express enduring sorrow.
"Vai Meu Samba" sends the song itself out as a messenger. Maria Rita opens by asking it to "Vai dizer à vida" [Go tell life] "que a ferida não cicatrizou" [that the wound hasn't healed] — she's still stuck exactly where the breakup left her, saying so through the samba rather than to anyone directly.
The chorus asks the song to carry that admission into the open: "Deixa o sol bater, só pro mundo ver o que restou de mim" [Let the sun shine, just so the world can see what's left of me]. Built from two stanzas that repeat almost word for word, the lyric never resolves — it just keeps sending the same samba out again, which is the point.