The term 'booster engine' can be summarized as a turbocharged engine, which is an internal combustion engine that has been modified to increase its power output. This is done by forcing more air into the engine, allowing it to burn more fuel and generate more power. Turbochargers are typically used in high-performance vehicles, such as sports cars, to give them an extra boost of power. They are also used in some commercial and industrial applications, such as large trucks and construction equipment.