Downstream/ˌdaʊnˈstriːm/ Definition 1 of 5Pro Tip 1/2Directional Movement Use 'downstream' to describe something moving with the water's flow in rivers or streams. We watched the leaves go downstream. Pro Tip 2/2Easily Effortless 'Downstream' can imply moving without effort, as the current carries objects away. The kayak went downstream smoothly.