ice sheet

noun

1. a broad, thick sheet of ice covering an extensive area for a long period of time.
2. a glacier covering a large fraction of a continent.

noun

1. a thick layer of ice covering a large area of land for a long time, esp those in Antarctica and Greenland

1. A large sheet of ice and snow that covers an entire region and spreads out under its own weight. Ice sheets have an area of more than 50,000 square km (19,500 square mi). Compare icecap.