Abstract: An adjustable nozzle applicator and method for the application of liquid to a surface including a main nozzle member and an insert nozzle portion positioned therein. The bottom floor of the main nozzle member is configured to form a trough for channeling and directing the liquid. The insert portion encloses part of the trough and is disposed adjacent but not touching a wall of the main nozzle member to create an output aperture port. At the output aperture port, the liquid exits the aperture in a fashion resembling a waterfall without the use of any input pressure. Such a gentle waterfall flow of liquid is particularly useful for the application of liquids that are delicate in nature. Overflow liquid exits through the floor of the applicator. The width of the waterfall at the output may be varied by adjustment of the distance between the main nozzle member and the insert portion for precise control of the flow and application of the liquid.