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


a body so suspended from a fixed point as to move to and fro by the action of gravity and acquired momentum.
Horology. a swinging lever, weighted at the lower end, for regulating the speed of a clock mechanism.
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.

Origin of pendulum

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

Related forms

pen·du·lum·like, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for pendulum

British Dictionary definitions for pendulum


/ (ˈpɛndjʊləm) /


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)
such a device used to regulate a clockwork mechanism
something that changes its position, attitude, etc fairly regularlythe pendulum of public opinion

Word Origin for pendulum

C17: from Latin pendulus pendulous
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 pendulum


[ pĕnjə-ləm ]

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.