Sfanculo is a highly colloquial and vulgar Italian verb derived from "fare in culo" (to do in the ass), essentially meaning "to tell someone to f*** off" or "to send someone to hell". It's a strong expression of dismissal or contempt.
In the song, after a chaotic night, the singer and his friend Carnevale are lying on the ground. Carnevale is laughing hysterically, and the singer says, "E io che lo sfanculo e poi mi aggiungo" (And I tell him to f*** off and then I join him). This word perfectly captures the raw, rebellious, and somewhat cynical tone of the song, making it memorable and impactful.
Ready for a wild Friday night? Ligabue's song captures the feeling of needing to escape the pressures of the week. The narrator and his friend, Carnevale, head to an old club, feeling a bit out of place and older than they used to. The music is terrible and the place feels different, but they don't care. All they need is loud noise to forget their troubles because, after all, it's Friday.
The night takes a dark and intense turn. After an encounter with some younger guys escalates into a fight, the narrator finds himself with a gun to his throat. The chorus, a raw and defiant shout of "Non mi rompete i coglioni" (a very strong way of saying "Don't bother me"), becomes a desperate plea. Surviving the ordeal, he and his friend end up lying on the pavement outside, laughing at the absurdity and danger of it all. It's a story about a Friday night that goes from a simple escape to a life-threatening event, highlighting the chaos one might seek to feel alive.