Desencontro is a beautiful Portuguese word that literally means an 'un-meeting' or 'failed encounter'. It's formed by adding the prefix des- (which implies negation or reversal) to encontro (meeting).
In the song, it perfectly describes the core theme: a relationship breakdown due to a fundamental mismatch or disconnection. The singer points out "Há um desencontro" (There is a disconnection), highlighting the sad reality that she and her partner are simply not on the same wavelength.
This song starts with one of the most direct breakups you'll ever hear. Vanessa da Mata doesn't waste any time, telling her partner, "É só isso / Não tem mais jeito / Acabou / Boa sorte" (That's it / There's no way / It's over / Good luck). She explains that everything the other person wants to give her is just too much, describing it as "pesado" (heavy) and saying "Não há paz" (There's no peace). It's not just what they give, but what they want from her, which she calls "irreais / expectativas / desleais" (unrealistic / expectations / unfair).
But the song isn't just about ending things. It takes an interesting turn when she wishes for her ex-partner to get better, but specifically to "se cure / Dessa pessoa / Que o aconselha" (get cured / From this person who advises you). It suggests someone else's bad influence might be the real problem. Ben Harper's English lines about "falling, falling / Into the night" add to the feeling of a final, inevitable end. The song closes with a simple truth: "Um bom encontro é de dois" (A good meeting is of two), meaning a relationship needs two people on the same page, and they just weren't.