The term 'Truck Stopper' is a job description for someone who operates the brakes on a truck. The crossword solution for this term is 'BRAKE, ' which is a five-letter word. Brakes are an essential part of any vehicle, as they are used to slow down or stop the vehicle. In the case of a truck, the brakes are even more important, as they must be able to stop the large and heavy vehicle quickly and safely. Therefore, the person responsible for operating the brakes on a truck is known as a Truck Stopper.