acceleration

American  

[ak-sel-uh-rey-shuhn, ik-] / ækˌsɛl əˈreɪ ʃən, ɪk- /

noun

1. the act of accelerating; increase of speed or velocity.

2. a change in velocity.

3. Mechanics. the time rate of change of velocity with respect to magnitude or direction; the derivative of velocity with respect to time.

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acceleration British  

/ ækˌsɛləˈreɪʃən /

noun

1. the act of accelerating or the state of being accelerated

2.  a.  the rate of increase of speed or the rate of change of velocity

3.  a.  the power to accelerate

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acceleration Scientific  

/ ăk-sĕl′ə-rā′shən /

1. The rate of change of the velocity of a moving body. An increase in the magnitude of the velocity of a moving body (an increase in speed) is called a positive acceleration; a decrease in speed is called a negative acceleration. Acceleration, like velocity, is a vector quantity, so any change in the direction of a moving body is also an acceleration. A moving body that follows a curved path, even when its speed remains constant, is undergoing acceleration.

2. See more at gravity relativity

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acceleration Cultural  

1. A change in the velocity of an object.

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Discover More

The most familiar kind of acceleration is a change in the speed of an object. An object that stays at the same speed but changes direction, however, is also being accelerated. (See force.)

Other Word Forms

• nonacceleration
  noun
• overacceleration
  noun
• reacceleration
  noun

Etymology

Origin of acceleration

First recorded in 1525–35, acceleration is from the Latin word accelerātiōn- (stem of accelerātiō ). See accelerate, -ion

Explanation

Acceleration is the act of increasing speed. When you buy a sports car, you want one that has great acceleration, so it can go from zero to 60 miles an hour in no time. Acceleration comes from the Latin word accelerationem, which means "a hastening." When you hasten, you hurry, so acceleration is a speeding-up. Maybe you are walking to an appointment and realize you will be late. You pick up your pace — that's acceleration. If the rain on a stormy day begins to come down faster, that too is acceleration. As you can see, acceleration isn't just for cars.

Example Sentences

In China, President Xi Jinping has called for a rapid acceleration of a new energy system, emphasizing massive development in wind, solar and hydropower to safeguard energy security.

From Salon • May 16, 2026

Because this same feature appears across many different types of particles, the findings strongly support theories suggesting that cosmic ray acceleration and movement through space are controlled by rigidity.

From Science Daily • May 14, 2026

The German business-software company reiterated its target of revenue growth acceleration in 2027.

From The Wall Street Journal • May 14, 2026

The answer is earnings, what Muir calls the largest mid-cycle earnings acceleration in history.

From MarketWatch • May 14, 2026

For the case of a dropped ball, x = gt2/2, where g is the acceleration due to gravity.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife