bushing vs packing

bushing

noun
  • 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. 

  • A threaded bushing: a fastener element that is inserted into an object, usually to add a threaded hole in a softer or thin material. 

  • An adapter for joining pipes of different size. 

  • A lining for an opening through which a conductor passes, providing insulation and mechanical protection for the conductor. 

  • 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. 

packing

noun
  • Material used to fill in the space around something, especially to make a piston etc. watertight or airtight. 

  • The gathering of birds, animals etc. into a pack. 

  • Material used to wrap a product for sale etc.; packaging. 

  • The forming of players into a scrum. 

  • The action of putting things together, especially of putting clothes into a suitcase for a journey. 

  • Special material used to fill containers or vessels for certain chemically related applications. 

  • A fee charged to cover the costs of packaging. 

  • The spatial arrangement of objects, items or constituent parts. 

How often have the words bushing and packing occurred in a corpus of books? (source: Google Ngram Viewer )