Collins English-English Dictionary

speed [spiːd]

1. 1. n the act or quality of acting or moving fast; rapidity

2. 2. n the rate at which something moves, is done, or acts

3. 3. n

4. 4. n [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

5. 5. n a rate of rotation, usually expressed in revolutions per unit time

6. 6. n

7. 7. n a gear ratio in a motor vehicle, bicycle, etc

8. 8. n (in combination)

   a three-speed gear

9. 9. n [photog] a numerical expression of the sensitivity to light of a particular type of film, paper, or plate - See also ISO rating

10. 10. n [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

11. 11. n a slang word for amphetamine

12. 12. n [archaic] prosperity or success

13. 13. vb to move or go or cause to move or go quickly

14. 14. vi. [intr] to drive (a motor vehicle) at a high speed, esp above legal limits

15. 15. vt. [tr] to help further the success or completion of

16. 16. vi. [intr] [slang] to take or be under the influence of amphetamines

17. 17. vi. [intr] to operate or run at a high speed

18. 18. vi.

19. 19. vi. [archaic] [intr] to prosper or succeed

20. 20. vt. [tr] to wish success to

21. 21. vt. See also speed up

22. 22. vt. [Etymology] Old English sped (originally in the sense: success); related to spowan to succeed, Latin spes hope, Old Slavonic speti to be lucky