What is the definition or description of: facet?

Part of a joint: A facet is a flat surface on a bone covered with cartilage. It is matched by another facet on an adjoining bone. In the spine, there are pairs (right & left) on each vertebra (spinal bone). The place where the facets come together forms a facet joint. It has a capsule and lining and joint fluid, just like other body joints.

Spine Joints: Facet joints are places on the spinal bones where two bones actually meet and articulate. Many times arthritis or inflammation can arise here and cause pain.