fifth force
noun
a theoretical force in nature in addition to the strong and weak forces, gravitation, and the electromagnetic force.
Origin of fifth force
First recorded in 1975–80
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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
fifth force
noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
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fifth force
[fĭfth]
The American Heritage® Science Dictionary
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