Answer:
In the context of furniture, a key plate refers to a metal or wooden plate that is typically used to secure and reinforce the joints of a piece of furniture, particularly those with dovetail or mortise and tenon joints. The key plate is often inserted into a slot or groove, creating a tightening effect to improve the overall stability and strength of the joint. It acts as a structural element, preventing the joint from loosening or separating over time. Decorative key and back plate, features of a Gothic cabinet.