ice age🔊

(scientific) A period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence of major polar ice sheets that reach the ocean and calve icebergs.UMass Lowell - A human-induced hothouse climate? https://web.archive.org/web/20190510115634/http://faculty.uml.edu/lweeden/documents/HumaninducedhothouseGSAToday.pdf

(colloquial) Any of several glacial periods (within a scientific ''ice age'') marked by episodes of extensive glaciation alternating with episodes of relative warmth (''interglacial'').