speed

American  

[speed] / spid /

noun

• speeds
  plural

1. rapidity in moving, going, traveling, proceeding, or performing; swiftness; celerity: the speed of sound.

   the speed of light;

   the speed of sound.

   Synonyms:

   hurry, expedition, dispatch, alacrity, fleetness

   Antonyms:

   slowness

2. relative rapidity in moving, going, etc.; rate of motion or progress.

   full speed ahead.

   Synonyms:

   hurry, expedition, dispatch, alacrity, fleetness

3. full, maximum, or optimum rate of motion.

   The car gets to speed in just nine seconds.

4. Automotive. a transmission gear ratio.

5. Photography.

   1. Also called film speed. the sensitivity of a film or paper to light, measured by an ASA or DIN index, which assigns low numbers to slow film and higher numbers to faster film.

   2. Also called shutter speed. the length of time a shutter is opened to expose the film or digital sensor inside the camera to light.

   3. the largest opening at which a lens can be used.

6. Slang. a stimulating drug, as caffeine, ephedrine, or especially methamphetamine or amphetamine.

7. Informal. a person or thing that is compatible with or typical of one's ability, personality, desires, etc..

   My speed is writing postcards on the porch while everyone else is tearing around the tennis court.

8. Archaic. success or prosperity.

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verb (used with object)

• speeds,
  present (3rd person singular)
• sped,
  past participle,  past
• speeded,
  past participle,  past (especially British)
• speeding
  present participle

1. to promote the success of (an affair, undertaking, etc.); further, forward, or expedite.

   Synonyms:

   favor, facilitate, advance

2. to direct (the steps, course, way, etc.) with speed.

3. to increase the rate of speed of (usually followed byup ).

   to speed up industrial production.

   Synonyms:

   accelerate

4. to bring to a particular speed, as a machine.

5. to cause to move, go, or proceed with speed.

6. to expedite the going of.

   to speed the parting guest.

7. Archaic. to cause to succeed or prosper.

verb (used without object)

• speeds,
  present (3rd person singular)
• sped,
  past participle,  past
• speeded,
  past participle,  past (especially British)
• speeding
  present participle

1. to move, go, pass, or proceed with speed or rapidity.

2. to drive a vehicle at a rate that exceeds the legally established maximum.

   He was arrested for speeding.

3. to increase the rate of speed or progress (usually followed byup ).

4. to get on or fare in a specified or particular manner.

5. Archaic. to succeed or prosper.

idioms

1. at full / top speed,

   1. at the greatest speed possible.

      We drove down the highway at full speed.

   2. to the maximum of one's capabilities; with great rapidity.

      He worked at full speed.

2. up to speed,

   1. operating at full or optimum speed.

   2. functioning or producing at an expected, acceptable, or competitive level; up to par.

      a new firm not yet up to speed.

speed British  

/ spiːd /

noun

1. the act or quality of acting or moving fast; rapidity

2. the rate at which something moves, is done, or acts

3. physics a scalar measure of the rate of movement of a body expressed either as the distance travelled divided by the time taken ( average speed ) or the rate of change of position with respect to time at a particular point ( instantaneous speed ). It is measured in metres per second, miles per hour, etc

4. a rate of rotation, usually expressed in revolutions per unit time

5. 1. a gear ratio in a motor vehicle, bicycle, etc

   2. ( in combination )

      a three-speed gear

6. photog a numerical expression of the sensitivity to light of a particular type of film, paper, or plate See also ISO rating

7. photog a measure of the ability of a lens to pass light from an object to the image position, determined by the aperture and also the transmitting power of the lens. It increases as the f-number is decreased and vice versa

8. a slang word for amphetamine

9. archaic prosperity or success

10. quickly

11. 1. operating at an acceptable or competitive level

    2. in possession of all the relevant or necessary information

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verb

1. to move or go or cause to move or go quickly

2. (intr) to drive (a motor vehicle) at a high speed, esp above legal limits

3. (tr) to help further the success or completion of

4. slang (intr) to take or be under the influence of amphetamines

5. (intr) to operate or run at a high speed

6. archaic

   1. (intr) to prosper or succeed

   2. (tr) to wish success to

speed Scientific  

/ spēd /

1. The ratio of the distance traveled by an object (regardless of its direction) to the time required to travel that distance.

2. Compare velocity

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speed More Idioms  

More idioms and phrases containing speed

• full speed ahead
• up to par (speed)

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Synonym Usage

Speed, velocity, quickness, rapidity, celerity, haste refer to swift or energetic movement or operation. Speed (originally prosperity or success) may apply to human or nonhuman activity and emphasizes the rate in time at which something travels or operates: the speed of light, of a lens, of an automobile, of thought. Velocity, a more learned or technical term, is sometimes interchangeable with speed : the velocity of light; it is commonly used to refer to high rates of speed, linear or circular: velocity of a projectile. Quickness, a native word, and rapidity, a synonym of Latin origin, suggest speed of movement or operation on a small or subordinate scale; quickness applies more to people ( quickness of mind, of perception, of bodily movement ), rapidity more to things, often in a technical or mechanical context: the rapidity of moving parts; a lens of great rapidity. Celerity, a somewhat literary synonym of Latin origin, refers usually to human movement or operation and emphasizes expedition, dispatch, or economy in an activity: the celerity of his response. Haste refers to the energetic activity of human beings under stress; it often suggests lack of opportunity for care or thought: to marry in haste; a report prepared in haste. See rush ¹.

Other Word Forms

Derived Forms

• speeder
  noun
• speedfulness
  noun
• speedingness
  noun
• overspeed
  verb
• outspeed
  verb (used with object)
• multispeed
  adjective
• speedful
  adjective
• speedless
  adjective
• speedfully
  adverb
• speedingly
  adverb

Inflected Forms

Nouns

• speeds
  plural

Participles

• speeding
  present
• sped
  past
• speeded
  past

Conjugated Forms

Present

• speed
  simple
• speeds
  simple
• have sped
  perfect
• have speeded
  perfect
• has sped
  perfect
• has speeded
  perfect
• am speeding
  progressive
• are speeding
  progressive
• is speeding
  progressive
• have been speeding
  perfect progressive
• has been speeding
  perfect progressive

Past

• sped
  simple
• speeded
  simple
• had sped
  perfect
• had speeded
  perfect
• was speeding
  progressive
• were speeding
  progressive
• had been speeding
  perfect progressive

Future

• will speed
  simple
• will have sped
  perfect
• will have speeded
  perfect
• will be speeding
  progressive
• will have been speeding
  perfect progressive

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Etymology

Origin of speed

First recorded before 900; 1965–70 speed for def. 6; (noun) Middle English spede “good luck, prosperity, rapidity,” Old English spēd; cognate with Dutch spoed, Old High German spōt; akin to Old English spōwan “to prosper, succeed”; (verb) Middle English speden “to succeed, prosper, go with speed,” Old English spēdan “to succeed, prosper”; cognate with Old Saxon spōdian, Old High German spuoten

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Explanation

Speed most often describes acceleration or a high rate of motion. When something picks up too much speed, it can run off course, like a kid on a bike zooming uncontrollably down a steep hill. Speed can be a noun or verb. As a noun, it's an indicator of pace, as in the speed of a car. As a noun, it's also a drug that keeps you awake, very awake. As a verb, it means to “move along quickly,” like how you speed around on your bike. A fun fact: while speed refers to the distance traveled by an object during a specific amount of time, velocity describes that distance, but in a specified direction.

Example Sentences

See Examples For:

speed speeds sped speeded speeding

“We have the chance to double down on all the things that are working to speed up the recovery process, and that’s what is so exciting about this moment.”

From Los Angeles Times ● Nov. 14, 2026

"I don't think I ever lost my love for the game, it was more 'Will I come back and be able to bowl the same and will the air speed be there?'"

From BBC ● Nov. 13, 2026

AI is drastically amplifying the threat, helping automate searches for vulnerabilities and scan for openings at breakneck speed.

From The Wall Street Journal ● Nov. 13, 2026

These will form part of the Starlink constellation that provides high speed internet from space.

From BBC ● Nov. 13, 2026

It made a ticking noise as it churned through Enigma settings at incredible speed, eliminating wrong solutions far faster than possible by hand.

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

Additionally, expect gusty southwest to northwest winds throughout the day Friday, with sustained wind speeds around 20 mph with possible gusts of 30 to 35 mph across the inland region of Los Angeles County.

From Los Angeles Times ● Nov. 12, 2026

Road administration director Galin Kostov added that speeds were unsuitable for the conditions, which included wet road surfaces, and the motorway would remain closed until it had been cleared, BTA reported.

From BBC ● Nov. 10, 2026

Because neutrinos interact so rarely with other particles, they can cross vast distances at speeds approaching the speed of light.

From Science Daily ● Nov. 2, 2026

Virginia’s program has faced early glitches, including devices picking up lower speed limits from nearby roads and restricting car speeds.

From The Wall Street Journal ● Nov. 2, 2026

McGhee’s vessel could reach speeds up to sixty-five miles an hour, which was much faster than any Coast Guard patrol boat could travel.

From "1919 The Year That Changed America" by Martin W. Sandler

The leather-jacketed Huang has been CEO of Nvidia since the beginning, and he savvily pivoted the corporation’s focus once the generative A.I. boom sped off.

From Slate ● Nov. 12, 2026

“Everybody thinks we sped that scene up,” Farrelly says.

From Los Angeles Times ● Nov. 4, 2026

Not far from the cyclist's starting point, a black Volvo XC90 was already catching the attention of other drivers as it sped "erratically" along the semi-rural roads on the outskirts of Trafford and north-east Cheshire.

From BBC ● Oct. 30, 2026

Zuckerberg sped up Muse's launch due to Instinct's popularity, the New York Times reported.

From Barron's ● Oct. 12, 2026

The gnome repeated the message in a croaky little voice and then sped off to deliver it, chanting, “Message for Red! Message for Red!” over and over.

From "Rump: The (Fairly) True Story of Rumpelstilskin" by Liesl Shurtliff

It wasn’t long before USC finally speeded away from Iowa, with Desmond Claude and Saint Thomas taking control to close out the Hawkeyes.

From Los Angeles Times ● Jan. 15, 2025

However, earlier this year the UK's spending watchdog, the National Audit Office warned that this target would be missed unless the process was speeded up.

From BBC ● Dec. 2, 2024

EU leaders agreed at a summit on Thursday that returns of irregular migrants should be speeded up.

From BBC ● Oct. 18, 2024

The move speeded things up but raised concerns of potential corruption — a worry Syniehubov asserted was overstated.

From Seattle Times ● May 1, 2024

Speculation was useless; he speeded up his pace.

From "Redwall" by Brian Jacques

Mann sees AI changing the industry by speeding up the cycle of work.

From The Wall Street Journal ● Nov. 13, 2026

"Rave culture was a huge factor in speeding the tempo up. Once it got to 160bpm and now it's 170bpm, that felt like home for us," he said.

From BBC ● Oct. 31, 2026

Although the findings provide strong statistical evidence that global warming is speeding up, the study was not designed to determine exactly why the acceleration has occurred.

From Science Daily ● Oct. 30, 2026

One of the summit's major outcomes is the "global review": a set of concrete recommendations for turning lagging pledges into action and speeding up progress to the 2030 deadline.

From Barron's ● Oct. 30, 2026

For William Bateson, the English biologist, the conversion took about an hour—the time spent on a speeding train between Cambridge and London in May 1900.*

From "The Gene" by Siddhartha Mukherjee

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Related Words

• advance
• boost
• expedite
• facilitate
• fly
• further
• hasten
• help
• hurry
• promote
• quicken
• ride
• run
• rush
• zoom

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