Apreço translates to 'esteem' or 'regard'. It's a more formal and profound word than common synonyms like 'gosto' (liking) or 'carinho' (affection), suggesting a deep respect and value for someone.
In the song, the narrator admits, "Sei que não mereço todo o teu apreço" (I know I don't deserve all your esteem). This use highlights a sense of unworthiness and emphasizes the high regard the other person holds for them, making it a poignant and interesting word choice.