pendulum

American  

[pen-juh-luhm, pen-duh-] / ˈpɛn dʒə ləm, ˈpɛn də- /

noun

1. a body so suspended from a fixed point as to move to and fro by the action of gravity and acquired momentum.

2. Horology. a swinging lever, weighted at the lower end, for regulating the speed of a clock mechanism.

3. something that tends to move from one position, condition, etc., to the opposite extreme and then back again.

   In a democratic society, the pendulum of political thought swings left and right.

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pendulum British  

/ ˈpɛndjʊləm /

noun

1. a body mounted so that it can swing freely under the influence of gravity. It is either a bob hung on a light thread ( simple pendulum ) or a more complex structure ( compound pendulum )

2. such a device used to regulate a clockwork mechanism

3. something that changes its position, attitude, etc fairly regularly

   the pendulum of public opinion

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pendulum Scientific  

/ pĕn′jə-ləm /

1. A mass hung from a fixed support so that it is able to swing freely under the influence of gravity. Since the motion of pendulums is regular and periodic, they are often used to regulate the action of various devices, especially clocks.

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Other Word Forms

• pendulumlike
  adjective

Etymology

Origin of pendulum

1650–60; < New Latin, noun use of neuter of Latin pendulus pendulous

Explanation

A pendulum is something hanging and swinging freely from a fixed point. A grandfather clock might use for timekeeping a pendulum that swings back and forth. Pendulum comes from the Latin word pendulous, meaning "hanging down." If someone hangs a pocket watch in front of you and swings it back and forth, saying, "You're getting very sleepy," they're mimicking the movement of a pendulum. We also use the word pendulum to describe a situation moving between two poles or across a spectrum, like the balance of power in a multiparty political system.

Example Sentences

Academics I spoke with all emphasized that the state of A.I. detection is much better today than it was in 2023 but cautioned against letting the narrative pendulum swing too far in the other direction.

From Slate • Apr. 17, 2026

While analysts say it will take longer than a couple of months of elevated gas prices to swing the pendulum completely to favor EVs, pain at the pump already has some buyers thinking differently.

From The Wall Street Journal • Apr. 11, 2026

Levy: I always like to pull the pendulum back as far as possible.

From Los Angeles Times • Apr. 1, 2026

The pendulum would swing towards the dominant MCO partner in Chelsea.

From BBC • Feb. 5, 2026

Before his pendulum swing took him back toward Alby, he reached out for another vine, catching a nice thick one.

From "The Maze Runner" by James Dashner

Related Words

• timer