冲积层 chōngjīcéng alluvium Origin Definitions Defs Strokes Stroke Words Sentences Sents 冲积 沖積 chōngjī alluviate; alluviation to wash down and deposit sand, gravel, or soil in low-lying areas via water flow; the process or result of such deposition层 層 céng noun layer A physical sheet, thickness of material, or stratum covering a surface