Contramão literally means "wrong way" or "against traffic". It's an interesting word because it evokes a sense of daring and going against the norm.
In the song, the singer uses it metaphorically when he sings, "E nas curvas do seu corpo / Invadir a contramão" (And on the curves of your body / Invade the wrong way). This suggests a passionate, almost reckless desire to get close to the person, breaking conventional boundaries in his pursuit of love.
"Contramão" ("Wrong Way") is a sertanejo love song by Gustavo Mioto featuring Dorgival Dantas about the rush of new attraction.
The singer wants to know what perfume the person he's falling for wears, because he says his life has felt scentless and he already knows he wants to give them a new one. He's careful not to rush or scare them off, but admits his kiss already wants to live in their smile.
The title comes from the chorus: he wants to trace the curves of their body and "invade the wrong lane," crashing head-on into their chest, an S.O.S. for his heart. He describes meeting love just by looking at them, feeling almost frozen before they arrived to warm him up, and realizing he had been flying too long and just wants to land.