Fragilidad translates to "fragility" or "delicacy". It's a beautiful and somewhat less common word in everyday song lyrics, making it stand out.
In "Mi Ángel de Amor," Belinda sings, "siento tu fragilidad mi amor" (I feel your fragility, my love). This line expresses a tender and protective sentiment towards the person she loves, highlighting their vulnerability and her desire to care for them. It adds a layer of depth and emotional nuance to the song.