n.
(高山等上之)常积不消的冰,冰盖

[ noun ]
a mass of ice and snow that permanently covers a large area of land (e.g., the polar regions or a mountain peak)
<noun.object>

icecap \ice"cap`\ ([imac]s"k[a^]p`) n.
a mass of ice and snow that permanently covers a large area
of land (e.g., the polar regions or a mountain peak).
[WordNet 1.5]