逆流溯源 nìliúsùyuán to go back to the source Definitions Defs Origin Strokes Stroke Words Sentences Sents 逆流 nìliú to go against the current To move or swim against the direction of the water flow; to go upstream溯源 sùyuán to trace back to the source To trace a river upstream to its headwaters; also used to mean investigating the origin or root cause of something.
