- a jet engine having a large impeller that takes in air, part of which is used in combustion of fuel, the remainder being mixed with the products of combustion to form a low-velocity exhaust jet.
- a type of by-pass engine in which a large fan driven by a turbine and housed in a short duct forces air rearwards around the exhaust gases in order to increase the propulsive thrust
- an aircraft driven by one or more turbofans
- the ducted fan in such an engine
