noun
Pleistocene epoch
Geological term for the epoch from about 2.6 million to 11,700 years ago, characterized by repeated glaciations.
更新世には氷河が広がっていた。
During the Pleistocene, glaciers were widespread.
From 更新 (kōshin, 'renewal') + 世 (sei, 'epoch'), a calque of the English 'Pleistocene' (from Greek pleistos 'most' + kainos 'new').