noun · soil or ground that is frozen, including both seasonally frozen ground and permafrost

在寒冷的北方，冬季挖掘冻土是一项极其艰巨的任务。

noun · a cold, treeless geographic region characterized by permanently frozen subsoil

这片广袤的极地冻土带是迁徙驯鹿的夏季栖息地。