(n) a sneak attack from the twat to the anus, while simultaneously making the sound of a train (i.e Woo! Woo!) entering a tunnel. After which the train sound signaling to your friends hidden about the room, and the you run a train on that bitch (chug-a-chug-a-choo-choo).
last night i pulled an amtrack on this bitch. (Most famous example of The Amtrack: Caligula.