The term AUTO GEAR is composed of six words related to the operation of a car. TRANNY (6 letters) is short for transmission, which is the system of gears that allows the car to change speed and direction. REV (3 letters) is an abbreviation for revolution, which is the number of times a car's engine turns over in a single minute. DRIVE (5 letters) is the act of controlling a car's motion by pressing the accelerator and brake pedals. COG (3 letters) is a wheel with teeth that fit into the teeth of another wheel, allowing them to move together. FIRST (5 letters) is the gear used when starting a car from a stopped position. REVERSE (7 letters) is the gear used to make the car move backwards.