Nile River Hairline

Listen here, you smooth-brained buffoon, you can't even comprehend a simple diss. You see, the Nile is a long river, and your hairline is... well, it's not exactly full. By comparing your receding hairline to the Nile, this joke is highlighting the length and the way it meanders, get it? It's a playful way of saying your hairline is going backward.