(1)   Changing location rapidly
(2)   A central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression
(3)   A rate (usually rapid) at which something happens
"The project advanced with gratifying speed"
(4)   The ratio of the focal length to the diameter of a (camera) lens system
(5)   Distance travelled per unit time


(6)   Move faster
"The car accelerated"
(7)   Cause to move faster
"He accelerated the car"
(8)   Move very fast
"The runner zipped past us at breakneck speed"
(9)   Travel at an excessive or illegal velocity
"I got a ticket for speeding"
(10)   Step on it
"He rushed down the hall to receive his guests"
"The cars raced down the street"


spēd, from Germanic *spodiz. Cognate with Dutch spoed.


  1. the state of moving quickly or the capacity for rapid motion; rapidity
  2. the rate of motion or action, specifically / the magnitude of the velocity; the rate distance is traversed in a given time
  3. the sensitivity to light of film, plates.
  4. any amphetamine drug used as a stimulant, especially illegally, especially methamphetamine
  5. luck, success, prosperity

Usage notes



  1. To succeed; to prosper, be lucky.
    • 1485, Sir Thomas Malory, Le Morte Darthur, Book I:
      he and alle his knyghtes haue assayed it and none can spede.
  2. To help someone, to give them fortune.
    God speed, until we meet again.
  3. To go fast, especially excessively fast.
    The Ferrari was speeding along the road.
  4. To exceed the speed limit.
    Why do you speed when the road is so icy?
  5. To be under the influence of stimulant drugs, especially amphetamines.

Usage notes

The Cambridge Guide to English Usage indicates that sped is for objects in motion (the race car sped) while speeded is used for activities or processes, but notes that the British English convention does not hold in American English.