an area reduced almost to a plain by erosion.
Origin of peneplain
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a relatively flat land surface produced by a long period of erosion
Word Origin for peneplain
C19: from pene- + plain 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012