General English

  • noun the rate at which something moves or is done
  • verb to move quickly

Cars & Driving

  • noun the rate of movement
  • noun a gear or gear ratio


  • The rate at which motion occurs. Also, the magnitude of a velocity. Speed is a scalar quantity, while velocity is a vector quantity. Speed is usually measured as the distance traveled per unit time. angular speed is the change in direction per unit time.
  • The rate at which something occurs. For example, a communications speed.
  • One of multiple available rates of operation. For example, extended play.
  • A specific rate of operation. For example, a CPU speed.
  • A relative rate of operation. For example, double speed.
  • A rating which expresses the sensitivity of a given photographic medium, such as film or paper, to light.
  • A measure of the ability of a lens to accumulate light at a given aperture.

Media Studies

  • noun a measure of the sensitivity of photographic film to light, expressed according to any of various numerical rating systems


  • noun a measure of the sensitivity of a photographic material to light


  • noun an amphetamine drug. The word was first applied in the 1960s to methedrine, a powerful stimulant. By 1968 it was becoming the generic term for all amphetamines (which literally ‘speed up’ the nervous system).


  • verb to drive a car faster than the legal speed

Origin & History of “speed”

Speed originally meant ‘success, prosperity’ – and when you wish someone Godspeed, you are wishing them ‘good fortune’. Largely, though, it is the secondary sense ‘quickness’, which first emerged in the late Old English period, that has survived to the present day. It has a surviving Germanic relative in Dutch spoed ‘quickness’, and it also has possible links with Old church Slavonic speti ‘succeed’. It was first used as a slang term for ‘amphetamine’ in the mid 1960s.