bushing

noun

1. A type of bearing, a cylindrical lining designed to reduce friction and wear inside a hole, often used as a casing for a shaft, pin or hinge.
2. An elastic bearing used as a type of vibration isolator, commonly made of rubber. An interface between two parts, damping the movement and the energy transmitted.
3. A threaded bushing, is a fastener element that is inserted into an object, usually to add a threaded hole in a softer or thin material.
4. A lining for an opening through which a conductor passes, providing insulation and mechanical protection for the conductor.