The Chinese word 追溯 (zhuīsù) is a compound verb formed by combining two characters with related meanings to create a nuanced concept: 追 means "to chase" or "to pursue", while 溯 means "to go upstream" or "to trace back to a source". Together, they form a metaphorical image of pursuing or chasing something backward along its course, against the flow of time or events, to arrive at its origin or root cause, thus meaning "to trace back to", "to date from", or "to investigate the origin of".