冻土 dòngtǔ frozen earth Origin Definitions Defs Strokes Stroke Words Sentences Sents 冻土层 dòngtǔcéng permafrost a subsurface layer of soil that remains frozen throughout the year, often found in polar regions or at high altitudes永久冻土 yǒngjiǔdòngtǔ permafrost 永冻土 yǒngdòngtǔ permafrost