Together, the characters literally mean “entrust it to the east flow.” The combination creates a poetic and final image of total loss, rooted in the geography of China itself.
The phrase 付之东流 is deeply embedded in the Chinese geographical and literary consciousness. It evokes a grand, natural, and unstoppable force—the relentless eastward flow of China's great rivers into the vast ocean. This isn't just about something being wasted; it's about it being swept away by fate or circumstances beyond one's control, disappearing forever. A comparable Western idiom might be “gone down the drain” or “all for naught.” However, “gone down the drain” has a more mundane, almost clumsy connotation of something accidentally lost in the plumbing. 付之东流 is more literary, tragic, and grand. It connects the loss to the powerful, indifferent forces of nature, suggesting a sense of finality and often, great sorrow or regret. It reflects a worldview where human efforts, no matter how great, can sometimes be dwarfed by larger currents of events.
付之东流 is a formal idiom (chengyu) but is widely understood and used in situations that involve a significant loss of effort, time, or resources. It's almost always negative and expresses disappointment or frustration.