- the power of water used, or capable of being used, to drive machinery, turbines, etc.
- a waterfall or descent in a watercourse capable of being so used.
- a water right possessed by a mill.
- the power latent in a dynamic or static head of water as used to drive machinery, esp for generating electricity
- a source of such power, such as a drop in the level of a river, etc
- the right to the use of water for such a purpose, as possessed by a water mill
