泝 sù go upstream Origin Definitions Defs Strokes Stroke Words Sentences Sents 泝洄 sùhuí to go upstream to go against the current; to travel upstream泝游 sùyóu go upstream (variant form) to move or travel against the current of a river泝源 sùyuán to trace back to the source To investigate the origin of something; to trace a river upstream to its source.