The motion of the elastic ball bouncing freely on the ground and its motion between parallel walls are also reciprocating, why not mechanical vibration?

The reciprocating motion of an object near the equilibrium position (the pendulum is usually within 5) is called mechanical vibration, which is called vibration for short. We take the force that the vibrating object has been subjected to when it deviates from the equilibrium position, which is called restoring force. From this point of view, the object must be subjected to restoring force after deviating from the equilibrium position, which is a necessary condition for mechanical vibration. (1) Definition: An object or a part of an object moves back and forth along a straight line or an arc on both sides of a central position (equilibrium position), which is called mechanical vibration. It is characterized by "reciprocating motion". (2) The vibrating object is subjected to restoring force, and the restoring force is zero at the equilibrium position. (3) Restoring force is a force named after the action of force, which is provided by the resultant force in the direction of motion. * * * * * * * The motion of the elastic ball seems to conform to the mode of vibration, but it does not conform to the point of "restoring force" and has no equilibrium position.