Waterwheel

Part of speech: noun

Definitions

1. A structure featuring a wheel that rotates when driven by flowing water, harnessing energy to operate machinery or assist in agricultural processes
2. An engineering device that utilizes the movement of water to turn a wheel, generating power for tasks such as grinding grain or pumping water
3. A mechanical apparatus designed to rotate via the force of flowing water, converting hydraulic energy into mechanical work for functions like milling or irrigation

Etymology: A waterwheel is about as transparent as compounds get: "water" and "wheel" placed side by side, with the sense that the wheel is driven by flowing water. The older and more common spelling keeps the two parts apart as "water wheel," and the joined form is simply a later typographical variant of that same two-word term. Nothing about its construction hides a deeper story. What makes the device itself notable is its long reach into the past. Waterwheels were used to lift water for irrigation and to power grinding, sawing and later textile machinery, so the word has always named a practical, everyday machine rather than a figure of speech. Its meaning has therefore stayed almost exactly as literal as the parts suggest.

Synonyms: mill wheel, watermill, hydraulic wheel