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[dee-sel-uh-reyt] /diˈsɛl əˌreɪt/
verb (used with object), decelerated, decelerating.
to decrease the velocity of:
He decelerates the bobsled when he nears a curve.
to slow the rate of increase of:
efforts to decelerate inflation.
verb (used without object), decelerated, decelerating.
to slow down:
The plane decelerated just before landing.
Origin of decelerate
1895-1900; de- + (ac)celerate
Related forms
deceleration, noun
decelerator, noun
nondeceleration, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2016.
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Examples from the Web for deceleration
Historical Examples
  • Then her blasting discharges subsided to the power necessary to match exactly the Chicago's deceleration.

    Triplanetary Edward Elmer Smith
  • Casker nodded and punched a deceleration spiral into the ship's tape.

    One Man's Poison Robert Sheckley
  • "No, we'll use our acceleration for pseudograv halfway, and deceleration the other half," Jacquemont told him.

    The Cosmic Computer Henry Beam Piper
  • The ship quivered for just a second as it shifted over into deceleration.

    An Empty Bottle Mari Wolf
  • Their deceleration was like the pull of gravity, and now straight ahead seemed down.

  • Ekstrohm fingered loose the cinches of his deceleration couch.

  • You're the only member we have, who's inside the grounds here, who can stand the acceleration and deceleration.

    By Earthlight Bryce Walton
  • In a few seconds the pressure of deceleration pushed at them.

    Rip Foster in Ride the Gray Planet Harold Leland Goodwin
  • At 25 miles high there was as horrible a vibration and as deadly a deceleration as at the air-graze.

    Space Tug Murray Leinster
  • Allowing for deceleration, three successive predictions of its landing point agreed.

    Operation Terror William Fitzgerald Jenkins
British Dictionary definitions for deceleration


to slow down or cause to slow down
Derived Forms
deceleration, noun
decelerator, noun
Word Origin
C19: from de- + accelerate
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
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Word Origin and History for deceleration

1894, originally in railroading, coined from de- "do the opposite of" (see de-) + (ac)celeration.

Verily "deceleration" is a word which could only be coined by the Great Western. ["Engineering," Feb. 2, 1894]



1899, back-formation from deceleration. Related: Decelerated; decelerating.

Online Etymology Dictionary, © 2010 Douglas Harper
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