A glacial covering or ice-cap extending over a large area of country, as that which is believed by many geologists to have covered much of eastern North America during the glacial period.(noun)
The Century Dictionary (Public Domain)
Use "ice-sheet" in a sentence
"Too often the reasons we disagree about what to do about climate change are framed in this way, as disputes about the truth claims of some aspect of biogeophysical science – is the world warming; are greenhouse gases responsible; will this ice-sheet collapse?"
"I have often thought that that cold winter was a fore-runner of the countless cold winters to come, as the ice-sheet from farther north crept down over the face of the land."
"When the Yukon shut up shop and went to sleep under a three-foot ice-sheet, this peripatetic couple found themselves at the Five Finger Rapids, with the City of Gold still a journey of many sleeps to the north."