An estate car, also known as a station wagon, is a type of car that has an extended roof and a large cargo area. It is typically used for carrying large amounts of luggage or other items. The term 'estate car' comes from the fact that it was originally designed to transport the belongings of wealthy families. The crossword solution for this term is 'BRAKE, ' which refers to the braking system of the car. Brakes are an important safety feature that allow the driver to slow down or stop the vehicle.