WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a wheel that rotates by direct action of water; a simple turbine
n. a wheel with buckets attached to its rim; raises water from a stream or pond
Word Usage
"The Magenn MARS tethered balloon, which rotates in the breeze similar to an old-fashioned waterwheel, is designed to provide power to small villages in lesser developed countries (think most of Africa)."