A bottle of Jack Daniels, which is a popular whiskey.
daughter: "....Brush my teeth with a bottle of jack, cuz when i leave for the night, i ain't com..."
father: "Stop right there, young lady! What on earth is a bottle of jack?!"
daughter: "I have no clue...it's just part of the song."
father: "I'm going to urban dictionary that sh*t."
son: "Bottle of Jack is a term for a whiskey, called Jack Daniels."
father: "gee wizz....Thanks son! stop listening to that song, dear. Kesha is a drunken slut."
daughter: "Daddy, you're ruining my life!"