National Service is a term used to describe a variety of activities that involve serving the nation in some capacity. RENTAL (6 letters) is a term used to describe the process of renting something, such as a car or other item. Rentals (7 letters) is a term used to describe the items that are being rented. Rentacar (8 letters) is a term used to describe a company that specializes in renting cars. All three terms are related to National Service, as they involve providing a service to the nation.