Dedicaste is the past tense of the verb dedicar (to dedicate). It's a beautifully romantic word that is central to the song's theme of love and heartbreak.
In the lyrics, the singer is torturing himself by "Oyendo las canciones que un día me dedicaste" (Listening to the songs that you once dedicated to me). This single word captures the bittersweet pain of remembering a special, loving gesture from a relationship that has now ended, making it incredibly poignant and memorable.
This song is for anyone who has ever tried to get over an ex but just... can't. The singer is going through all the classic breakup motions. He says, "Te bloqueé de Insta" (I blocked you on Insta), but then immediately admits, "pero por otra cuenta veo tus historias" (but I see your stories from another account). He even deletes their number, but what's the point? He knows it by heart anyway. It's this honest and slightly funny struggle that makes the song so good.
He knows the relationship was bad for him, admitting "Me hiciste daño / Y así te extraño" (You hurt me / And still I miss you). Instead of avoiding the pain, he drives right into it, cruising "por las calles / Que me besaste" (through the streets / where you kissed me) and listening to the songs they shared. He wants to ask his ex to come back but knows "eso no se pide" (you don't ask for that). So, all he can do is ask God for strength, which feels like a very real and vulnerable moment in the middle of a heartbreak.