noun \ˈspēd\

: the rate at which someone or something moves or travels

: the rate at which something happens or is done

: the quality of being quick

Full Definition of SPEED

archaic :  prosperity in an undertaking :  success
a :  the act or state of moving swiftly :  swiftness
b :  rate of motion: as
(1) :  velocity 1 (2) :  the magnitude of a velocity irrespective of direction
c :  impetus
:  swiftness or rate of performance or action :  velocity 3a
a :  the sensitivity of a photographic film, plate, or paper expressed numerically
b :  the light-gathering power of a lens or optical system
c :  the time during which a camera shutter is open
:  a transmission gear in automotive vehicles or bicycles —usually used in combination <a ten-speed bicycle>
:  someone or something that appeals to one's taste <just my speed>
:  methamphetamine; also :  a related stimulant drug and especially an amphetamine
speed·ster \ˈspēd-stər\ noun
at speed
chiefly British
:  fast, rapidly
up to speed
:  operating at full effectiveness or potential

Examples of SPEED

  1. This instrument measures wind speed.
  2. The machine was operating at high speed.
  3. traveling at nearly the speed of light
  4. Under the right conditions the car can reach speeds over 200 miles an hour.
  5. The vehicle maintained a speed of 40 miles per hour.
  6. The work was done with remarkable speed.
  7. This computer works at a much faster processing speed than my old one.
  8. The machine chops up tree branches and leaves with speed and ease.

Origin of SPEED

Middle English spede, from Old English spēd; akin to Old High German spuot prosperity, speed, Old English spōwan to succeed, Latin spes hope, Lithuanian spėti to be in time
First Known Use: before 12th century



: to move fast

: to move (someone or something) somewhere very quickly

: to drive faster than the legal speed limit

sped \ˈsped\ or speed·edspeed·ing

Full Definition of SPEED

intransitive verb
a archaic :  to prosper in an undertaking
b archaic :  get along, fare
a :  to make haste <sped to her bedside>
b :  to go or drive at excessive or illegal speed
:  to move, work, or take place faster :  accelerate <the heart speeds up>
transitive verb
a archaic :  to cause or help to prosper :  aid
b :  to further the success of
a :  to cause to move quickly :  hasten
b :  to wish Godspeed to
c :  to increase the speed of :  accelerate
:  to send out <speed an arrow>
speed·er noun

Examples of SPEED

  1. A group of kids sped past us on their bikes.
  2. They jumped in the car and sped away.
  3. A car was speeding down the street.
  4. An ambulance sped her to the hospital.
  5. I got pulled over twice last month because I was speeding on the highway.

First Known Use of SPEED

before 12th century


noun \ˈspēd\   (Medical Dictionary)

Medical Definition of SPEED



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