pendulum
//ˈpɛn.djʊ.ləm//
Noun
pendulumSingular
pendulumsPlural
1
A weight hung from a fixed point so that it can swing freely back and forth under the influence of gravity, especially used to regulate the mechanism of a clock.
The grandfather clock has a beautiful brass pendulum that swings back and forth.
2
Something that swings back and forth between two states, opinions, or conditions.
The political pendulum has swung back toward conservatism.