noun, verb, sped or speed⋅ed, speed⋅ing.| 1. | rapidity in moving, going, traveling, proceeding, or performing; swiftness; celerity: the speed of light; the speed of sound. |
| 2. | relative rapidity in moving, going, etc.; rate of motion or progress: full speed ahead. |
| 3. | full, maximum, or optimum rate of motion: The car gets to speed in just nine seconds. |
| 4. | Automotive. a transmission gear ratio. |
| 5. | Photography.
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| 6. | Slang. a stimulating drug, as caffeine, ephedrine, or esp. methamphetamine or amphetamine. |
| 7. | Informal. a person or thing that is compatible with or typical of one's ability, personality, desires, etc.: My speed is writing postcards on the porch while everyone else is tearing around the tennis court. |
| 8. | Archaic. success or prosperity. |
| 9. | to promote the success of (an affair, undertaking, etc.); further, forward, or expedite. |
| 10. | to direct (the steps, course, way, etc.) with speed. |
| 11. | to increase the rate of speed of (usually fol. by up): to speed up industrial production. |
| 12. | to bring to a particular speed, as a machine. |
| 13. | to cause to move, go, or proceed with speed. |
| 14. | to expedite the going of: to speed the parting guest. |
| 15. | Archaic. to cause to succeed or prosper. |
| 16. | to move, go, pass, or proceed with speed or rapidity. |
| 17. | to drive a vehicle at a rate that exceeds the legally established maximum: He was arrested for speeding. |
| 18. | to increase the rate of speed or progress (usually fol. by up). |
| 19. | to get on or fare in a specified or particular manner. |
| 20. | Archaic. to succeed or prosper. |
| 21. | at full or top speed,
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| 22. | up to speed,
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| a number corresponding to the ratio of the focal length to the diameter of a lens system, esp. a camera lens. In f/1.4, 1.4 is the f-number and signifies that the focal length of the lens is 1.4 times as great as the diameter. Abbreviation: f/, f/, f, f: |

speed (spēd) n.
v. tr.
[Middle English spede, from Old English spēd, success, swiftness; see spē- in Indo-European roots.] Synonyms: These verbs mean to proceed or cause to proceed rapidly or more rapidly. Speed refers to swift motion or action: The train sped through the countryside. Postal workers labored overtime to speed delivery of the holiday mail. Word History: We learn from the fable of the tortoise and the hare that the race is not always to the swift, but etymology teaches us that speed and success are closely related. The Old English word spēd, from which our word speed is descended, originally meant "prosperity, successful outcome, ability, or quickness." A corresponding verb, spēdan, in Modern English the verb speed, meant "to succeed, prosper, or achieve a goal"; and an adjective, spēdig, the ancestor of our word speedy, meant "wealthy, powerful." Except for archaic uses the words today relate only to the general sense of "velocity." The meaning "success" is retained chiefly in the compound Godspeed, a noun formed from the phrase meaning "May God cause you to prosper." |
speed
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SPEED
Early system on LGP-30. Listed in CACM 2(5):16 (May 1959).
speed
In addition to the idiom beginning with speed, also see full speed ahead; up to par (speed).
speed
in photography, any of those standards that indicate (1) the size of the lens opening, or aperture, (2) the duration of exposure, and (3) the sensitivity of the film to light.
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