A more thorough explanation:

vis fluminis

Vis fluminis is a legal term that refers to the force of a river or stream. It is the power that water exerts as it flows.

One example of vis fluminis is the energy that can be harnessed from a waterfall to generate electricity. Another example is the force of a river that can erode the banks and change the landscape over time.

These examples illustrate the definition of vis fluminis because they both involve the power of water in motion. In the first example, the force of the water is used to create energy. In the second example, the force of the water is powerful enough to shape the land around it.