What is the definition of the Engine mount of a rocket?

An engine when running will vibrate. If directly fixed to the supporting structure then this vibration would transmit through the vehicle or structure body. These vibrations lead to noise and mechanical damage in adjoining structures. The engine mount is typically a rubber to metal bonded component which is used to 'mount' the engine onto the structure. The rubber element is used to absorb or 'dampen' the vibrations, reducing noise and increasing the service life of the surrounding structures and components. Try searching for 'anti vibration mountings'. Some companies which manufacture engine mounts are: - AV Industrial Products Ltd