[ak-sel-uh-rey-shuh n]


the act of accelerating; increase of speed or velocity.
a change in velocity.
Mechanics. the time rate of change of velocity with respect to magnitude or direction; the derivative of velocity with respect to time.

Origin of acceleration

First recorded in 1525–35, acceleration is from the Latin word accelerātiōn- (stem of accelerātiō). See accelerate, -ion
Related formsnon·ac·cel·er·a·tion, nouno·ver·ac·cel·er·a·tion, nounre·ac·cel·er·a·tion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for acceleration

expedition, quickening, dispatch, stimulation, hurrying, spurring

Examples from the Web for acceleration

Contemporary Examples of acceleration

Historical Examples of acceleration

  • "Get on the acceleration couch," said Marcus as he did so himself.

    Mezzerow Loves Company

    Floyd L. Wallace

  • Wilbur awakened with a start, sitting on the edge of the acceleration diaphragm.

    Mezzerow Loves Company

    Floyd L. Wallace

  • The Ardan missiles were powered for an acceleration of one hundred gravities.

    Masters of Space

    Edward Elmer Smith

  • You do not really employ that barbarous method of acceleration?

    The Adventures of Harry Revel

    Sir Arthur Thomas Quiller-Couch

  • "All the other Gerns are by now in their acceleration couches," he said.

    Space Prison

    Tom Godwin

British Dictionary definitions for acceleration



the act of accelerating or the state of being accelerated
the rate of increase of speed or the rate of change of velocitySymbol: a
the power to accelerateSymbol: a
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

Word Origin and History for acceleration

1530s, from Latin accelerationem (nominative acceleratio) "a hastening," noun of action from past participle stem of accelerare (see accelerate).

Online Etymology Dictionary, © 2010 Douglas Harper

acceleration in Science



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

acceleration in Culture


A change in the velocity of an object.


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.)
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.