Gistro is a slang term, particularly used in some Caribbean Spanish dialects, to refer to someone's buttocks or rear end. It's a playful and somewhat provocative word that you won't find in a standard dictionary.
In "PROBLEMA," Daddy Yankee uses gistro to describe a woman's captivating dance moves, specifically when she's dancing low. The line "Le dio hasta abajo y se le vio el gistro" (She went all the way down and her gistro was seen) highlights the visual and energetic nature of the reggaeton dance style, making the word memorable and central to the song's vibe.
Daddy Yankee sings about a woman who is impossible to ignore. She is confident, trendy (he compares her to a TikTok challenge), and every one of her friends notices her walk into a room. He calls her "un problema" (a problem), but it is a compliment: she messes with his head in the best way.
This is a party track built for perreo (reggaeton dancing). The chorus repeats the hook so it sticks in your head, and the outro breaks into pure dance-floor chanting ("perreando", "fuego"). It is playful and flirtatious rather than romantic.
The lyrics lean heavily on reggaeton slang and dropped final consonants ("conflicto" becomes "conflicto'", "dijimos" becomes "dijimo'"), which is typical of how the genre is actually sung and a great real-world listening exercise.