rapidity in moving, going, traveling, proceeding, or performing; swiftness; celerity: the speed of light;the speed of sound.
relative rapidity in moving, going, etc.; rate of motion or progress: full speed ahead.
full, maximum, or optimum rate of motion: The car gets to speed in just nine seconds.
Automotive. a transmission gear ratio.
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.
Also called shutter speed . the length of time a shutter is opened to expose the film or digital sensor inside the camera to light.
the largest opening at which a lens can be used.
Slang. a stimulating drug, as caffeine, ephedrine, or especially methamphetamine or amphetamine.
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.
Archaic. success or prosperity.
to promote the success of (an affair, undertaking, etc.); further, forward, or expedite.
to direct (the steps, course, way, etc.) with speed.
to increase the rate of speed of (usually followed by up): to speed up industrial production.
to bring to a particular speed, as a machine.
to cause to move, go, or proceed with speed.
to expedite the going of: to speed the parting guest.
Archaic. to cause to succeed or prosper.
to move, go, pass, or proceed with speed or rapidity.
to drive a vehicle at a rate that exceeds the legally established maximum: He was arrested for speeding.
to increase the rate of speed or progress (usually followed by up).
to get on or fare in a specified or particular manner.
Archaic. to succeed or prosper.
Idioms about speed
at full / top speed,
at the greatest speed possible: We drove down the highway at full speed.
to the maximum of one's capabilities; with great rapidity: He worked at full speed.
up to speed,
operating at full or optimum speed.
functioning or producing at an expected, acceptable, or competitive level; up to par: a new firm not yet up to speed.
- speedful, adjective
- speed·ful·ly, adverb
- speed·ful·ness, noun
- speed·ing·ly, adverb
- speed·ing·ness, noun
- speedless, adjective
- mul·ti·speed, adjective
- outspeed, verb (used with object), out·sped or out·speed·ed, out·speed·ing.
- o·ver·speed, verb, o·ver·sped or o·ver·speed·ed, o·ver·speed·ing.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use speed in a sentence
Since then, total hours worked have rebounded at exactly the same speed.Despite wildly different approaches, the US and UK are seeing identical declines in hours worked | Dan Kopf | September 17, 2020 | Quartz
The discovery of this phenomenon, which theorists called universality, was as bizarre as finding that elephants and egrets move at precisely the same top speed.How Mathematical ‘Hocus-Pocus’ Saved Particle Physics | Charlie Wood | September 17, 2020 | Quanta Magazine
Added to which, a page that’s been properly optimized for speed might not need AMP for those speed gains, as well.Google ranking factors to change search in 2021: Core Web Vitals, E-A-T, or AMP? | Aleh Barysevich | September 16, 2020 | Search Engine Watch
You can coach sharpness within speeds, so that means how you start, how you push off and how you maintain your sprint speed by the technique that you use.A Canadian Teenager Is One Of The Fastest Soccer Players In The World | Julian McKenzie | September 16, 2020 | FiveThirtyEight
As the next flare runs into the protons released by the previous flare, it would accelerate protons and electrons in the same direction at the same speeds.Neutrinos could reveal how fast radio bursts are launched | Lisa Grossman | September 16, 2020 | Science News
Term limits could be a prescription to speed change along.
He felt his body grow limp (like one of those high-speed films of a flower wilting).Powerful Congressman Writes About ‘Fleshy Breasts’ | Asawin Suebsaeng | January 7, 2015 | THE DAILY BEAST
The jet engine instantly brought two advances over propellers: it doubled the speed and it was far more reliable.Flight 8501 Poses Question: Are Modern Jets Too Automated to Fly? | Clive Irving | January 4, 2015 | THE DAILY BEAST
One report has the AirAsia Airbus flying at a speed very close to what would trigger a low speed stall.
Authorities blame anarchists protesting a proposed high-speed rail line called TAV that will link Turin and Lyon, France.
Really, he had made astonishing speed for one who had tunnelled his way underp.The Tale of Grandfather Mole | Arthur Scott Bailey
A long stretch of smooth ice followed, over which he glided with ever-increasing speed.The Giant of the North | R.M. Ballantyne
Never again would he sit behind that wheel rejoicing in the insolence of speed.The Joyous Adventures of Aristide Pujol | William J. Locke
In fact, his appearance was so formidable that Davy did not pause for a second look, but started off at the top of his speed.Davy and The Goblin | Charles E. Carryl
And the girl, scarce believing her good fortune, departed with a speed that bordered on the ludicrous.St. Martin's Summer | Rafael Sabatini
British Dictionary definitions for speed
the act or quality of acting or moving fast; rapidity
the rate at which something moves, is done, or acts
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
a rate of rotation, usually expressed in revolutions per unit time
a gear ratio in a motor vehicle, bicycle, etc
(in combination): a three-speed gear
photog a numerical expression of the sensitivity to light of a particular type of film, paper, or plate: See also ISO rating
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
a slang word for amphetamine
archaic prosperity or success
at speed quickly
up to speed
operating at an acceptable or competitive level
in possession of all the relevant or necessary information
to move or go or cause to move or go quickly
(intr) to drive (a motor vehicle) at a high speed, esp above legal limits
(tr) to help further the success or completion of
(intr) slang to take or be under the influence of amphetamines
(intr) to operate or run at a high speed
(intr) to prosper or succeed
(tr) to wish success to
- See also speed up
- speeder, noun
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
Scientific definitions for speed
The ratio of the distance traveled by an object (regardless of its direction) to the time required to travel that distance. Compare velocity.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Other Idioms and Phrases with speed
In addition to the idiom beginning with speed
- speed up
- full speed ahead
- up to par (speed)
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.