The term 'Truck Driver's Compartment' refers to the area of a truck where the driver is seated. This area is also known as the CAB, which is a three-letter word that can be used to solve the crossword puzzle. The CAB is typically located at the front of the truck and is designed to provide the driver with a comfortable and safe environment while driving. It is usually equipped with a variety of features such as air conditioning, power windows, and a radio.