The term 'LONG TRUCK' can be solved by the four-letter word 'SEMI'. A SEMI-truck, also known as a tractor-trailer, is a large truck used for transporting goods over long distances. It consists of a tractor unit, which is the cab of the truck, and one or more trailers, which are attached to the tractor unit. SEMI-trucks are commonly used in the transportation industry, and are often seen on highways and interstates.