afterburnerˈæf tərˌbɜr nər, ˈɑf-
a device injects fuel into a hot exhaust for extra thrust
A device in the engine of an aircraft which injects fuel into the exhaust system to increase the thrust.
An afterburner is an additional component present on some jet engines, mostly military supersonic aircraft. Its purpose is to provide an increase in thrust, usually for supersonic flight, takeoff and for combat situations. Afterburning is achieved by injecting additional fuel into the jet pipe downstream of the turbine. The advantage of afterburning is significantly increased thrust; the disadvantage is its very high fuel consumption and inefficiency, though this is often regarded as acceptable for the short periods during which it is usually used. Pilots can activate and deactivate afterburners in-flight and jet engines are referred to as operating wet when afterburning is being used and dry when not. An engine producing maximum thrust wet is at maximum power, while an engine producing maximum thrust dry is at military power.