decelerate

American  

[dee-sel-uh-rayt] / diˈsɛl əˌreɪt /

Also deaccelerate

verb (used with object)

• decelerates,
  present (3rd person singular)
• decelerated,
  past participle,  past
• decelerating
  present participle

1. to decrease the velocity of.

   He decelerates the bobsled when he nears a curve.

2. to slow the rate of increase of.

   efforts to decelerate inflation.

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verb (used without object)

• decelerates,
  present (3rd person singular)
• decelerated,
  past participle,  past
• decelerating
  present participle

1. to slow down.

   The plane decelerated just before landing.

decelerate British  

/ diːˈsɛləˌreɪt /

verb

1. to slow down or cause to slow down

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Other Word Forms

Derived Forms

• deceleration
  noun
• decelerator
  noun

Inflected Forms

Participles

• decelerating
  present
• decelerated
  past

Conjugated Forms

Present

• decelerate
  simple
• decelerates
  simple
• have decelerated
  perfect
• has decelerated
  perfect
• am decelerating
  progressive
• are decelerating
  progressive
• is decelerating
  progressive
• have been decelerating
  perfect progressive
• has been decelerating
  perfect progressive

Past

• decelerated
  simple
• had decelerated
  perfect
• was decelerating
  progressive
• were decelerating
  progressive
• had been decelerating
  perfect progressive

Future

• will decelerate
  simple
• will have decelerated
  perfect
• will be decelerating
  progressive
• will have been decelerating
  perfect progressive

Etymology

Origin of decelerate

First recorded in 1895–1900; de- + (ac)celerate

Explanation

Use the verb decelerate when you want to slow down, like when you realize you are missing important moments in life by racing around, trying to do everything yourself. If you make an effort to decelerate, you might be happier — and healthier. Decelerate is the opposite of accelerate, which means "to go faster." Decelerate often describes slowing a vehicle, but it can relate to nearly anything, like a friendship that begins with hanging out nearly every day but decelerates when you move to a new town or get busy with school and sports. It doesn't mean the friendship is ending or over, just that the pace is now a little slower.

Example Sentences

See Examples For:

decelerate decelerates decelerated decelerating

Electric vehicles can also accelerate and decelerate much more quickly than conventional combustion cars, which Di Giulio says can cause motion sickness.

From BBC ● Oct. 3, 2026

“Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously,” it states.

From Salon ● Sep. 13, 2026

Morgan analyst Doug Anmuth was encouraged by Meta’s increased advertising revenue, although he expects sales growth to decelerate throughout the year and sees a more “challenging” path to returns outside of advertising.

From MarketWatch ● Apr. 30, 2026

It's very light but strong enough to produce the drag that we need to decelerate.

From Barron's ● Apr. 10, 2026

In Darwin's scheme, the rate of change of an organism was generally fixed, while the rate of natural selection could be amplified to accelerate evolution or dampened to decelerate it.

From "The Gene" by Siddhartha Mukherjee

The plane decelerates rapidly from a ground speed of 598 knots to 390 knots in 45 seconds.

From The Wall Street Journal ● Oct. 3, 2026

“Even if growth in data center decelerates slightly next year,” the analysts said Texas Instruments’ total revenue should be able to grow by about 20%.

From MarketWatch ● Sep. 18, 2026

It decelerates the vehicle from about 350 miles per hour to about 17 miles per hour for a nice soft landing for the crew in the Pacific Ocean.

From Barron's ● Apr. 10, 2026

“It could just be the de-ce. I don’t know,” Redick said, alluding to the way Doncic decelerates with the ball in his hands.

From Los Angeles Times ● Dec. 22, 2025

The low hum of a centrifuge decelerates until it stops.

From "The Last Cuentista" by Donna Barba Higuera

U.K. headline inflation decelerated to 2.6% in June from 2.8% in May, coming in below analysts’ expectations of 2.7% in The Wall Street Journal’s poll.

From The Wall Street Journal ● Jul. 22, 2026

Growth in cloud applications decelerated by 2 percentage points on a sequential basis, to 9%, “keeping the SaaSpocalypse theory alive,” according to Thill.

From MarketWatch ● Jun. 11, 2026

China’s consumer spending growth decelerated to its weakest pace since 2022 in April, while industrial output, investment and the real-estate sector all continued to deteriorate, falling short of economists’ expectations.

From The Wall Street Journal ● May 31, 2026

Annual sales growth has decelerated over the past five years through 2025, and is expected to slow further this year, leaving it less room to fend off threats like X Money.

From MarketWatch ● Apr. 16, 2026

First, we descended from Hermes, and decelerated our orbital velocity so we could start falling properly.

From "The Martian" by Andy Weir

To start, investors are much more optimistic about the economy’s strength, and think it can handle a 5% yield without quickly decelerating.

From The Wall Street Journal ● Sep. 14, 2026

The study directly responds to research from a South Korean team that claimed the universe may have entered a period of decelerating expansion.

From Science Daily ● Aug. 29, 2026

Declining oil prices are likely to send the main PCE index decelerating to around 3.5% by year-end, top Fed officials and Wall Street economists predict.

From MarketWatch ● Jun. 25, 2026

He said AI capital spending — with the four major hyperscalers looking to spend $700 billion on AI infrastructure this year — is actually accelerating, not decelerating.

From MarketWatch ● Jun. 10, 2026

On the backstretch, he was going along smoothly when, without warning, he threw his forelegs forward and propped, decelerating rapidly and dropping back through the field.

From "Seabiscuit: An American Legend" by Laura Hillenbrand