Any of the four basic forces that act on matter, comprising the strong, weak, electromagnetic, and gravitational forces. In the fundamental interactions between subatomic particles, the fundamental forces act to change the energy and momentum of an existing particle, to destroy an existing particle, or to create new particles.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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