Panal translates to "honeycomb". It's a sweet and evocative word that isn't commonly found in everyday Spanish songs.
In "Acércate A Mi," the lyrics describe a lover's lips as "esa boquita tan dulce como el panal" (that little mouth as sweet as the honeycomb). This beautiful simile paints a vivid picture of the sweetness and allure of the beloved, making it a memorable and enticing word choice.
The whole song runs on one excuse. He is cold, and the only cure happens to be her standing closer: "No te alejes tanto, porque yo siento frío" (Don't move so far away, because I feel cold). Los Ángeles Azules set that plea to a cumbia beat, so it arrives cheerful instead of desperate. What he asks for in return is small and oddly specific. Not a kiss at first, just a sigh: "Acércate a mí, regalándome un suspiro" (Come closer to me, giving me a sigh).
Then he pushes his luck. He wants her lips, and the mouth he is after gets the best image in the song: "Esa boquita tan dulce como el panal" (That sweet little mouth, sweet as honeycomb). The sighing turns dangerous too, because he keeps announcing that "Y este suspiro me va a matar" (And this sigh is going to kill me), which is a lot of drama for a man who has not been kissed yet. That is the joke the song is in on. Everything here is first-love scale, enormous and a bit silly, and the accordion keeps it moving so nobody has to take the cold too seriously.