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.

---

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

---

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

---

acceleration Cultural  

1. A change in the velocity of an object.

---

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

Derived Forms

• nonacceleration
  noun
• reacceleration
  noun
• overacceleration
  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

Deputy Defense Secretary Steve Feinberg established a Munitions Acceleration Council in 2025 to increase production of 12 critical weapons, from Patriot interceptors to Long Range Anti-Ship Missiles.

From The Wall Street Journal • Mar. 20, 2026

Carvalho touted Ed as an AI-enhanced student advisor that was to be a component of a unique Individual Acceleration Plan, or IAP, for every student.

From Los Angeles Times • Feb. 27, 2026

The government says that work is already underway through the Remediation Acceleration Plan "to make sure those responsible for the cladding crisis pay their fair share".

From BBC • Dec. 22, 2024

He announced that the U.N. is launching a “Gender Equality Acceleration Plan” to support governments in designing and implementing policies and spending that respond to the needs of women and girls.

From Seattle Times • Mar. 8, 2024

Acceleration of the respiratory rate where no physiological cause operates is due to a variety of conditions.

From Special Report on Diseases of the Horse by Michener, Charles B.