Full 18

A term most commonly used by car salesmen, describing a potential customer, who upon first analysis, is visiting the dealership with no intention or chance of buying a car, thereby existing solely to fuck the salesman so deep and hard out of their precious time and energy, that the fucking is akin to getting fucked by a fully aroused, 18-inch penis.

"Hey Jim, do you think you have a sale here?'' , inquired the sales manager. "

NO WAY"', replied Jim the salesman. "Full 18"!