My friend Matt invented the word a while back, so all credit goes to him. It basically describes the art of the rolling stop. And we all know about rolling stops, but not everybody knows that it's an art form. It has been mastered by nearly every St. Louis driver. The process: You gently slow down to a stop sign, and upon seeing that there is nobody around, gently roll through it. The key is in the smoothness of stoptional or else it's just a rolling stop. Everybody can do a rolling stop, and then punch the accelerator after the sign, but only St. Louisians are able to do it smoothly and with fluidity. Because seriously, when it's 1 am and you're on a country road who really wants to stop all the way at the sign.
Stoptional (n.) (stop-chi-nul): The art form that involves almost stopping at a stop sign, and smoothly exiting. Often seen in St. Louis drivers.