The term 'rotary engine' refers to an internal combustion engine that uses a rotary design to convert pressure into a rotating motion. This type of engine is most commonly used in aircraft, but can also be found in some cars and motorcycles. The term 'turbine' is a seven-letter word that is related to the rotary engine. A turbine is a device that uses the energy of a fluid or gas to create mechanical power. Turbines are often used in combination with a rotary engine to increase its efficiency and power output.