Temerario translates to "reckless" or "daring". It's a strong adjective that describes someone who takes risks without much thought for the consequences.
In the song, the artist uses it to describe the act of smelling his ex-partner's clothes daily, knowing she no longer loves him. He says, "Supongo que hay que ser un temerario para oler tu ropa a diario sabiendo que ya no me amas" (I guess you have to be reckless to smell your clothes daily knowing that you no longer love me). This word perfectly captures the raw, almost self-destructive vulnerability of holding onto a lost love.
AMBKOR's "Verte Otra Vez" is a really honest and emotional look at a breakup, full of regret and longing. He's clearly struggling, admitting, "De nuevo ciego, de nuevo el puto ego de un cobarde" [Again blind, again the damn ego of a coward], suggesting his own actions and pride played a part in the split. He misses the small, intimate moments, like talking to her "como un niño chico" [like a little kid] or calling her 'Cosita' [Little Thing].
The song is packed with vivid details that show just how much he's still living in the past. He mentions her clothes are "Sigue habiendo ropa tuya en el armario" [There's still your clothes in the closet] and that he even smells them daily, knowing she doesn't love him anymore. He desperately wishes he could go back in time, repeating, "Ojalá pudiera volver / Ojalá poder retroceder hasta el ayer y / Verte otra vez" [I wish I could go back / I wish I could go back to yesterday and / See you again]. It's a powerful and relatable feeling of wanting just one more glimpse, even if it's just to see her and not speak.