The term 'JET SPEED' can be broken down into two words, 'JET' and 'SPEED'. The word 'JET' is a four-letter word that refers to an aircraft powered by JET engines. JET engines are a type of propulsion system that uses a high-velocity stream of air to generate thrust. This type of engine is used in many types of aircraft, including commercial airliners, military jets, and private planes. The word 'SPEED' refers to the rate at which something moves or travels. In the context of JET engines, it refers to the SPEED at which the aircraft can travel. Therefore, the term 'JET SPEED' can be defined as the SPEED at which an aircraft powered by JET engines can travel.