fifth force

noun

a theoretical force in nature in addition to the strong and weak forces, gravitation, and the electromagnetic force.

Nearby words

fifth commandment, fifth cranial nerve, fifth dimension, fifth disease, fifth estate, fifth force, fifth monarchy, fifth monarchy men, fifth position, fifth republic, fifth wheel

Origin of fifth force

First recorded in 1975–80

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for fifth force

fifth force

noun

a hypothetical non-Newtonian repulsive component of the force of gravity, postulated as an addition to the four known fundamental forces (gravitational, electromagnetic, strong, and weak)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for fifth force

fifth force

[ fĭfth ]

Any of various hypothetical, very weak forces thought to cause bodies to repel each other. Such forces are occasionally considered as a solution to unexpected deviations in the measured value of the gravitational constant or to explain the apparent acceleration of very distant galaxies away from earth.