Definition
Peneplane is an alternative, though less common, spelling of peneplain. It also describes a vast area that has been reduced by erosion to a nearly flat surface, resembling a plain. Imagine an ancient mountain range worn down over millions of years. It's basically synonymous with peneplain. The term emphasizes the end result of long-term erosion processes, producing a low-relief landscape. Think of it as nature's way of hitting the reset button on topography.