A pediplain (from the Latin pes, genitive case pedis, meaning "foot") is a concept in geology and geomorphology that described extensive plains formed by the coalescence of pediments. The processes through which pediplains forms is known as pediplanation. The concepts of pediplain and pediplanation were first developed by geologist Lester Charles King in his 1942 book South African Scenery. The concept gained notoriety as it was juxtaposed to peneplanation.