A garbage disposal dishwasher cap is a device that seals the connection between a garbage disposal and a dishwasher drain hose to prevent water from backflowing into the garbage disposal. It typically features a rubber gasket to create a watertight seal and is designed to allow wastewater from the dishwasher to drain into the garbage disposal while preventing any potential leaks or clogs. The cap ensures that the proper flow of water is maintained and helps prevent any foul odors or unpleasant noises from entering the kitchen.