glacial epoch

noun
1.
Also called glacial period, ice age. the geologically recent Pleistocene Epoch, during which much of the Northern Hemisphere was covered by great ice sheets.
2.
any one of the Permian, Carboniferous, Cambrian, or Precambrian glaciations.
Origin
1840-50
British Dictionary definitions for glacial period

glacial period

noun
1.
any period of time during which a large part of the earth's surface was covered with ice, due to the advance of glaciers, as in the late Carboniferous period, and during most of the Pleistocene; glaciation
2.
(often capitals) the Pleistocene epoch
Brit equivalent glacial epoch, ice age