Poluída translates to "polluted". It's an intriguing word choice in a song, as it typically refers to environmental contamination.
In "Mente Poluída", the artist uses it metaphorically to describe a "polluted mind" or "polluted imagination". This suggests a mind filled with intrusive thoughts, perhaps anxieties, or even a creative mind that is overflowing with ideas to the point of being overwhelming. This unexpected usage makes the word memorable and thought-provoking.
This song is a hilarious and very direct look inside the mind of someone with a major crush. CEF Tanzy sings about being obsessed with a person who doesn't even know he exists, or at least doesn't give him any attention. On the outside, he pretends to be cool, singing, "Eu só te olho como alguém que não quer nada" (I only look at you like someone who wants nothing). But secretly, his imagination is running wild.
He calls his own mind "mente poluída" (polluted mind) because of all the detailed fantasies he has. He's so confident in his imaginary skills that he believes if she knew what he was thinking, "Ainda vais acabar teu namorado" (You would break up with your boyfriend). The song gets even more blunt when he explains that her ignoring him just "aumentas a minha obsessão" (increases my obsession), leading him to the "jogo imaginário, 5 contra 1" (the imaginary game, 5 against 1), which is a very cheeky slang for masturbation. It's a funny, over-the-top confession of a secret, one-sided love affair happening entirely in his head.