"The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word \"turbofan\" is a portmanteau of \"turbine\" and \"fan\": the turbo portion refers to a gas turbine engine which takes mechanical energy from combustion, and the fan, a ducted fan that uses the mechanical energy from the gas turbine to accelerate air rearwards."@en . . . .