adj. pleistocene, concerning the Pleistocene geological era

nm. Pleistocene, geological era in which much of the earth was covered in ice (approximately 2 million to 10000 years ago)

n. Pleistocene, geological era in which much of the earth was covered in ice (approximately 2 million to 10000 years ago)

= Pleistocene.
Ex: The recent study of archeological remains, particularly radiocarbon research, indicates that India has a very rich prehistory going back into the late Pleistocene period.