verb (used with object), sped or speed·ed, speed·ing.

verb (used without object), sped or speed·ed, speed·ing.


    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.
    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.

Origin of speed

before 900; 1965–70 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; (v.) Middle English speden to succeed, prosper, go with speed, Old English spēdan to succeed, prosper; cognate with Old Saxon spōdian, Old High German spuoten
Related formsspeed·ful, adjectivespeed·ful·ly, adverbspeed·ful·ness, nounspeed·ing·ly, adverbspeed·ing·ness, nounspeed·less, adjectivemul·ti·speed, adjectiveout·speed, 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.

Synonyms for speed

1, 2. fleetness, alacrity, dispatch, expedition; hurry. 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. 9. advance, favor. 11. accelerate. 16. See rush1.

Antonyms for speed

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for speed

Contemporary Examples of speed

Historical Examples of speed

  • All started at speed to meet her, but presently Mrs. Raymount sank on the grass.

    Weighed and Wanting

    George MacDonald

  • I pray you to speed a bolt against yonder shield with all your force.

    The White Company

    Arthur Conan Doyle

  • Here was speed, and with such stride—strong, and straight, and true!


    W. A. Fraser

  • Ye're planning to speed that thing before ye've got it off the jacks.

    Her Father's Daughter

    Gene Stratton-Porter

  • He ran with all the speed he had ever attained at a track meet.

    Her Father's Daughter

    Gene Stratton-Porter

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
  1. a gear ratio in a motor vehicle, bicycle, etc
  2. (in combination)a three-speed gear
photog a numerical expression of the sensitivity to light of a particular type of film, paper, or plateSee 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
  1. operating at an acceptable or competitive level
  2. in possession of all the relevant or necessary information

verb speeds, speeding, sped or speeded

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
  1. (intr)to prosper or succeed
  2. (tr)to wish success to
See also speed up
Derived Formsspeeder, noun

Word Origin for speed

Old English spēd (originally in the sense: success); related to spōwan to succeed, Latin spēs hope, Old Slavonic spěti to be lucky
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 speed

Old English sped "success, prosperity, advancement," from Proto-Germanic *spodiz (cf. Old Saxon spod "success," Dutch spoed "haste, speed," Old High German spuot "success," Old Saxon spodian "to cause to succeed," Middle Dutch spoeden, Old High German spuoten "to haste"), from PIE *spo-ti- "speed," from *spe- "to thrive, prosper" (cf. Sanskrit sphayate "increases," Latin sperare "to hope," Old Church Slavonic spechu "endeavor," Lithuanian speju "to have leisure").

Meaning "quickness of motion or progress" emerged in late Old English (usually adverbially, in dative plural, e.g. spedum feran), emerging fully in early Middle English. Meaning "gear of a machine" is attested from 1866. Meaning "methamphetamine, or a related drug," first attested 1967, from its effect on users. Speed bump is 1975; figurative sense is 1990s. Full speed is recorded from late 14c. Speed reading first attested 1965. Speedball "mix of cocaine and morphine or heroin" is recorded from 1909.


Old English spedan "to succeed, prosper, advance" (see speed (n.)). Meaning "to go fast" is attested from c.1300. Meaning "to send forth with quickness" is first recorded 1560s; that of "to increase the work rate of" (usually with up) is from 1856. Related: Speeded; speeding.

Online Etymology Dictionary, © 2010 Douglas Harper

Science 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.

Idioms and Phrases with speed


In addition to the idiom beginning with speed

  • speed up

also see:

  • 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.