A mixture of heroin and cocaine administered intravenously. This combination offers the best of both drugs. The lady (coke) gives you a rush of intense euphoria followed by the soporific effects of your boy (heroin), thus effectively eliminating the anxiety and depression that follows when shooting up cocaine by itself.
Me: I've never smoked crack but I've done speedballs.
You: You're fucking kidding me, right? You've shot up coke and smack? I'm breaking up with you, Dumbass.