Breu literally means 'pitch-darkness' or 'tar'. It's a less common word that evokes a strong, almost poetic image of profound darkness.
In "Chuva de Prata," the lyric "Pinga seu nome no breu pra ficar" (Drip your name in the darkness to stay) uses breu metaphorically. It suggests writing a loved one's name in a place so dark and enduring that it will remain forever, symbolizing an eternal mark of love. This makes it a unique and memorable word in the context of a romantic song.
"Chuva De Prata" opens by giving the sky an instruction. The moon is told to take its veil off and let the weather do the rest — "Se tem luar no céu / Retira o véu e faz chover / Sobre o nosso amor" ("If there's moonlight in the sky / Remove the veil and make it rain / Over our love") — and what comes down is silver, steady, and slow enough to hurt: "Chuva de prata que cai sem parar / Quase me mata de tanto esperar" ("Silver rain that falls non-stop / Almost kills me from waiting so long"). The waiting is the real subject. Everything the singer asks for is a way of ending it — a kiss to seal things, "Um beijo molhado de luz" ("A light-drenched kiss"), and the moon called back again and again to soak the two of them through.
The chorus stops asking and starts advising: "Toda vez que o amor disser, vem comigo / Vai sem medo / De se arrepender" ("Every time love says, come with me / Go fearlessly / Of regretting it"). Take the invitation and skip the part where you weigh it first. By the closing verse the request has shrunk to something a person can actually hand over — dance close, "Cola seu rosto no meu vem dançar" ("Press your face to mine, come dance"), and leave a name behind in the dark. Even the parting gets bargained down to the smallest possible favour: "Enquanto se esquece de mim / Lembra da canção" ("While you forget about me / Remember the song").