verb (used with object), de·cel·er·at·ed, de·cel·er·at·ing.

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), de·cel·er·at·ed, de·cel·er·at·ing.

to slow down: The plane decelerated just before landing.

Origin of decelerate

First recorded in 1895–1900; de- + (ac)celerate
Related formsde·cel·er·a·tion, nounde·cel·er·a·tor, nounnon·de·cel·er·a·tion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for decelerate

Contemporary Examples of decelerate

Historical Examples of decelerate

  • "We'll start to decelerate in about ten minutes," O'Brine said.

  • They could decelerate it at a rate of fifteen gravities or more.

    Space Tug

    Murray Leinster

  • Copeland worked the jury-rigged controls of the jet, continuing to decelerate.

    Comet's Burial

    Raymond Zinke Gallun

  • Its motor is designed to decelerate that mass by 1,075 mph in order to allow it to assume a descending orbit.

    Far from Home

    J.A. Taylor

  • They went in fast, using her gravity to help them curve into a forced orbit as they strained to decelerate.


    Carroll Mather Capps

British Dictionary definitions for decelerate



to slow down or cause to slow down
Derived Formsdeceleration, noundecelerator, noun

Word Origin for decelerate

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

Word Origin and History for decelerate

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

Online Etymology Dictionary, © 2010 Douglas Harper