A glacier is a large mass of ICE that moves slowly over land. The term 'glacier' can be broken down into two parts: ICE (3 letters) and ICECAP (6 letters). ICE refers to the frozen water that makes up the glacier, while ICECAP refers to the layer of snow and ICE that covers the top of the glacier. Together, these two terms describe the large, slow-moving mass of ICE that is found in many mountainous regions.