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

The concern is not only about closing speeds, but also about the sheer amount of acceleration the cars have now.

From BBC • Apr. 21, 2026

He said the company told analysts that there has been an acceleration in customer conversations since the disclosure of Neugebauer’s departure.

From MarketWatch • Apr. 20, 2026

Squali wrote that Amazon’s first-quarter results on April 29 should show sales acceleration at AWS along with above-industry growth across e-commerce and digital advertising.

From Barron's • Apr. 17, 2026

The IEA said there had been a rapid acceleration in US jet fuel exports in recent weeks.

From BBC • Apr. 16, 2026

One defined the acceleration of computer processing power, which allowed not just speed, but so many capabilities, including, at its core, interactivity; the other captured the rapid expansion of the communications network and its value.

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel