A fork of Rural Dictionary
The act of receiving oral sex.
A: "Yo, you should bang that chick." B: "She's not hot at all. Kinda ugly, actually. I think I'm going to try to find another girl." A: "Nah, nah... just cop a J."
To have sexual intercourse.
A: "I hung out with that cute blonde last night." B: "Did you derail?" A: "Hell yea. I derailed. So good."