oscillation

American  

[os-uh-ley-shuhn] / ˌɒs əˈleɪ ʃən /

noun

1. an act or instance of oscillating.

2. a single swing or movement in one direction of an oscillating body.

3. fluctuation between beliefs, opinions, conditions, etc.

4. Physics.

   1. an effect expressible as a quantity that repeatedly and regularly fluctuates above and below some mean value, as the pressure of a sound wave or the voltage of an alternating current.

   2. a single fluctuation between maximum and minimum values in such an effect.

5. Mathematics.

   1. the difference between the least upper bound and the greatest lower bound of the functional values of a function in a given interval.

   2. Also called saltus.  the limit of the oscillation in an interval containing a given point, as the length of the interval approaches zero.

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oscillation British  

/ ˈɒsɪlətərɪ, ˌɒsɪˈleɪʃən, -trɪ /

noun

1. physics statistics

   1. regular fluctuation in value, position, or state about a mean value, such as the variation in an alternating current or the regular swinging of a pendulum

   2. a single cycle of such a fluctuation

2. the act or process of oscillating

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oscillation Scientific  

/ ŏs′ə-lā′shən /

1. A repeating fluctuation in a physical object or quantity.

2. See also attractor harmonic motion

3. A single cycle of such fluctuation.

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Other Word Forms

• oscillatory
  adjective

Etymology

Origin of oscillation

1650–60; < Latin oscillātiōn- (stem of oscillātiō ) a swinging, equivalent to oscillāt ( us ) ( see oscillate) + -iōn- -ion

Explanation

Oscillation is the process of moving back and forth regularly, like the oscillation of a fan that cools off the whole room, or the oscillation of a movie plot that makes you laugh and cry. Oscillation is from the Latin word oscillare for "to swing," so oscillation is when something is swinging back and forth. Rumor has it if you trace the word back far enough, you get to the word for “a little face” of Bacchus, Greek god of wine, people used to hang up in vineyards to swing in the breeze. When there's oscillation, something is going back and forth, like a hanging sculpture going to and fro in the backyard.

Example Sentences

Oscillations are coordinated waves of neural firing that help different parts of the brain communicate with each other.

From Science Daily • Feb. 15, 2026

Oscillations in the birth rate sometimes made anxieties about a “baby bust” seem overstated.

From Slate • Oct. 7, 2025

DeWitt said very active Madden-Julian Oscillations this season brought “a lot of atmospheric river activity, as well as even some more traditional types of storms that don’t necessarily tap the tropical moisture.”

From Los Angeles Times • Mar. 7, 2023

"We don't know. We're just learning about the Pacific Decadal Oscillations and that they're important."

From US News • Mar. 19, 2015

Navigational sounding machine, 272 Newton, 195, 202 Nichol, John, Professor of English Language and Literature, 5 Nichol, John Pringle, Professor of Astronomy, 5, 20, 61, 63   Oersted, 61 Oscillations, electrical, 181 et seq.

From Lord Kelvin An account of his scientific life and work by Gray, Andrew

Related Words

• vibration