Reaction engines are devices that generate propulsion through the creation and expulsion of gases. Synonyms for reaction engines include jet engines, rocket engines, and afterburners. Jet engines are commonly used in commercial aviation, while rocket engines are used in space exploration and military applications. Afterburners are a type of jet engine that increases thrust by injecting additional fuel into the exhaust stream to create a secondary combustion process. Other synonyms for reaction engines include turbojet engines, turboprop engines, ramjet engines, and scramjet engines. Each of these types of engines has unique characteristics and applications, making them useful in a variety of industries, from aviation to military defense.