accelerate

accelerate — verb

1. of a car, train, or similar machine, to move at a higher speed than before, usua

1.verbintransitiveB2
Definition

of a car, train, or similar machine, to move at a higher speed than before, usually because the driver presses the gas pedal harder.

Example

The taxi accelerated as the traffic light turned green outside the station.

subject is a vehicle; intransitive use

Saoirse's small electric car can accelerate from zero to sixty in under five seconds.

accelerate from X to Y for speed range

Common collocations
  • accelerate from zero to sixty
  • accelerate sharply
  • accelerate smoothly
  • accelerate down the road
Synonyms
  • speed up

    everyday phrasal verb; less formal than 'accelerate'

  • pick up speed

    idiomatic; emphasises the gradual increase

Antonyms
  • decelerate

    formal; means to slow down

  • brake

    specific to vehicles; means to slow using the brake pedal

Grammar Patterns

[vehicle] + accelerates

accelerate from X to Y mph

Usage Note

Subject is almost always a vehicle or its driver. Distinguish from sense 2: this sense is reserved for engine-powered transport, while sense 2 covers people, animals, or other moving objects.

Common Mistakes

The taxi accelerated the speed.
The taxi accelerated.
in this sense the verb is intransitive; do not add 'the speed' as an object.

2. of a runner, animal, or moving thing, to start travelling at a quicker pace than

2.verbintransitiveC1
Definition

of a runner, animal, or moving thing, to start travelling at a quicker pace than the one being kept just before.

Example

On the final lap, Kofi accelerated and overtook two runners before the finish line.

subject is a person; intransitive

The cheetah accelerated across the dry grass and caught the young gazelle in seconds.

Common collocations
  • accelerate around the bend
  • accelerate down the slope
  • accelerate toward the finish
Synonyms
  • speed up

    neutral, everyday verb

  • quicken

    literary; often used of pace or steps

  • sprint

    specifically a sudden short burst of running

Antonyms

Grammar Patterns

[person/object] + accelerates

Usage Note

Subject is a person, animal, or non-vehicle object. Often used in sports reports and physics contexts. Distinguish from sense 1, which is reserved for engine-powered vehicles.

3. of a process or change, to take place at a quicker rate, or to push such a proce

3.verbtransitive / intransitiveC1
Definition

of a process or change, to take place at a quicker rate, or to push such a process to take place at a quicker rate.

Example

Climate scientists warn that warmer oceans are accelerating the melting of polar ice.

transitive: accelerate + noun (melting)

Online classes accelerated Pedro's progress through the second-year history course.

transitive: accelerate someone's progress

Common collocations
  • accelerate the decline
  • accelerate growth
  • accelerate the process
  • accelerate change
  • rapidly accelerate
Synonyms
  • speed up

    everyday equivalent for processes

  • hasten

    more formal; often suggests urgency

  • expedite

    formal; usually about official procedures

Antonyms
  • slow

    as a verb: to make a process happen more slowly

  • delay

    to push the timing later rather than make it quicker

  • decelerate

    formal; used of growth, inflation, or similar trends

Grammar Patterns

accelerate + noun (process/decline/growth)

[process] + accelerates

Usage Note

Subject or object is a non-physical process such as growth, decline, change, or progress. Distinguish from senses 1 and 2, where the subject physically moves through space.

Common Mistakes

The new drug accelerates patients to recover.
The new drug accelerates the recovery of patients.
'accelerate' takes a process or noun, not a person + to-infinitive.

4. to act on a moving body so that its physical speed becomes higher than it was a

4.verbtransitiveC1
Definition

to act on a moving body so that its physical speed becomes higher than it was a moment earlier.

Example

Powerful magnets in the long tunnel accelerate the tiny particles to nearly the speed of light.

transitive: accelerate + object (particles)

Strong winds accelerated the small wooden boat across the calm lake toward the harbour.

Common collocations
  • accelerate the particles
  • accelerate the object
  • accelerate it to high speed
Synonyms
  • speed up

    neutral; works in casual writing

  • propel

    emphasises pushing forward, not just speed

Antonyms

Grammar Patterns

accelerate + [moving object]

Usage Note

Common in physics and engineering. Subject is usually a force, engine, or field, and the object is the thing being made to move faster. Distinguish from sense 3, which acts on processes rather than physical motion.

Word family

  • acceleration
    nounB2
  • accelerator
    nounB2
  • accelerated
    adjectiveC1
  • accelerating
    adjectiveC1

Synonym discussion

Sense: verb/3

All four words describe making something happen at a quicker rate, but they fit different settings. 'Speed up' is the everyday choice and works for almost anything — traffic, work, conversation. 'Accelerate' is more formal and is the standard term in news, business, and science writing, especially for trends like growth, decline, or change. 'Hasten' is a literary verb that often carries a sense of urgency or even regret, as in 'her decision hastened his departure'. 'Expedite' is the most formal and almost always refers to official procedures, such as visa applications or shipping. Compare: 'The team sped up production' (neutral), 'The team accelerated production' (business report), 'Heavy rain hastened the harvest' (literary), 'Please expedite the paperwork' (formal request).

accelerate ↗speed up ↗hastenexpedite

Common collocations

Nouns

Adverbs

Phrases

  • accelerate from zero to sixty
  • accelerate the pace of change
  • accelerate the decline of

Prepositions

Etymology

LatinEnglish

Borrowed into English in the late 1500s from Latin 'acceleratus', the past participle of 'accelerare', meaning 'to quicken'. That Latin verb was built from 'ad-' ('toward') plus 'celer' ('swift'), the same root that gives us 'celerity'. Early uses in English referred mostly to making events happen sooner; the now-familiar sense of vehicles increasing speed appeared much later, alongside the rise of motor cars in the early twentieth century.