冻土 dòngtǔ frozen earth Origin Definitions Defs Strokes Stroke Words Sentences Sents 冻土层 dòngtǔcéng permafrost layer of frozen earth or soil; tundra永久冻土 yǒngjiǔdòngtǔ permafrost soil or rock that remains frozen for at least two consecutive years永冻土 yǒngdòngtǔ permafrost ever-frozen soil; permafrost