The Collaborative International Dictionary
Peneplain \Pe"ne*plain`\, n. [L. paene, pene, almost + E. plain.] (Phys. Geog.) A land surface reduced by erosion to the general condition of a plain, but not wholly devoid of hills; a base-level plain.
Wiktionary
n. (context geomorphology English) A low-relief plain representing the final stage of fluvial erosion during times of extended tectonic stability.
WordNet
n. a more or less level land surface representing and advanced stage of erosion undisturbed by crustal movements [syn: peneplane]
Wikipedia
In geomorphology and geology a peneplain is a low-relief non-constructional plain. This is the definition in the broadest of terms, albeit with frequency the usage of peneplain is meant to imply the representation of a near-final (or penultimate) stage of fluvial erosion during times of extended tectonic stability. Peneplains are sometimes associated with the cycle of erosion theory of William Morris Davis.
The existence of some peneplains, and peneplanation as a geomorphological process, is not without controversy, due to a lack of contemporary examples and uncertainty in identifying relic examples. By some definitions peneplains grade down to a base level represented by sea level, yet in other definitions such a condition is ignored. A common misconception about peneplains is that they ought to be featureless.
Usage examples of "peneplain".
Where ravines are he has plumbed lines to bring them to order and know them, has marked them and annotated his drawings, and learning the parameters of the peneplain or open-sided corries, the tributary canyons, creeks, rivers and fern-scruffed pampas, he has made them beautiful.
Later these ridges had been eroded away to peneplain by the pounding of unsettled water.
The opposite slopes were very gentle, merging so gradually into the general peneplain level of the continent that it was impossible to say decisively just where the range ended.
The undulations of the peneplain had gradually become perceptible as such, next as low mounds of marl studded with broken rock, and then the land abruptly crumpled itself into a succession of barren knolls.
Through the window, he could see the wing floating above an infinite expanse of cloudtop as flat and featureless as the peneplained landscapes of the Paleozoic.
It had an agriculture based on traditional principles, some FTZ-style assembly plants in closed compounds, and two or three towns of fifty or sixty thousand people, all on one peneplained continent in the Northern Hemisphere.
The expanse of the Northern Peneplain spread out below like a brown and ochre map of low relief, veined with dark green watercourses.