a body hung from a fixed point so as to swing freely to and fro under the combined forces of gravity and momentum: often used in regulating the movement of clocks
A body suspended from a fixed support so that it swings freely back and forth under the influence of gravity, commonly used to regulate various devices, especially clocks. Also called simple pendulum.
Something that swings back and forth from one course, opinion, or condition to another: the pendulum of public opinion.