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Blech. These are the grossest words.

perpetual-motion machine

perpetual-motion machine in Culture

perpetual-motion machine definition

A machine that could run forever. A perpetual-motion machine would have to produce at least as much energy as was needed for its operation. According to the second law of thermodynamics, such a machine is impossible, and to date none has ever been successfully demonstrated.

The American HeritageĀ® New Dictionary of Cultural Literacy, Third Edition
Copyright Ā© 2005 by Houghton Mifflin Company.
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