from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Physics The rate or a measure of the rate of motion, especially.
  • noun Distance traveled divided by the time of travel.
  • noun The limit of this quotient as the time of travel becomes vanishingly small; the first derivative of distance with respect to time.
  • noun The magnitude of a velocity.
  • noun Swiftness of action.
  • noun The act of moving rapidly.
  • noun The state of being in rapid motion; rapidity.
  • noun A transmission gear or set of gears in a motor vehicle.
  • noun A numerical expression of the sensitivity of a photographic film, plate, or paper to light.
  • noun The capacity of a lens to accumulate light at an appropriate aperture.
  • noun The length of time required or permitted for a camera shutter to open and admit light.
  • noun Slang A stimulant drug, especially amphetamine or methamphetamine.
  • noun Slang One that suits or appeals to a person's inclinations, skills, or character.
  • noun Archaic Prosperity; luck.
  • intransitive verb To go, move, or proceed quickly.
  • intransitive verb To drive at a speed exceeding a legal limit.
  • intransitive verb To pass quickly.
  • intransitive verb To move, work, or happen at a faster rate; accelerate.
  • intransitive verb Slang To be under the influence of a stimulant drug.
  • intransitive verb To prove successful; prosper.
  • intransitive verb To get along in a specified manner; fare.
  • intransitive verb To cause to move or proceed quickly; hasten.
  • intransitive verb To increase the speed or rate of; accelerate. Often used with up:
  • intransitive verb To further, promote, or expedite (a legal action, for example).
  • intransitive verb Archaic To help to succeed or prosper; aid.
  • idiom (up to speed) Operating at maximum speed.
  • idiom (up to speed) Producing something or performing at an acceptable rate or level.
  • idiom Informal (up to speed) Fully informed; conversant.

from The Century Dictionary.

  • noun Success; a successful course; prosperity in doing something; good fortune; luck: used either absolutely or relatively: as, to wish one good speed in an undertaking.
  • noun Apromoter of success or progress; a speeder.
  • noun Rapidity of movement; quickness of motion; swiftness: also used figuratively.
  • noun Rate of progress or motion (whether fast or slow); comparative rapidity; velocity: as, moderate speed; a fast or a slow rate of speed; to regulate the speed of machines.
  • noun In submarine rock-drilling, a leg or beam to which the drilling apparatus is attached.
  • noun Synonyms Swiftness, Rapidity, etc. (see quickness), expedition.
  • To advance toward a goal or a result; get on successfully; be fortunate; prosper; get on in general; make progress; fare; succeed.
  • To get on rapidly; move with celerity; hasten in going; go quickly; hasten in doing something; act rapidly; hurry; be quick.
  • To cause to advance toward success; favor the course or cause of; make prosperous.
  • To push forward; carry toward a conclusion; promote; advance.
  • To send or push forward in a course; promote the going or progress of; cause to go; aid in going.
  • To give high speed to; put to speed; hasten the going or progress of; make or cause to be rapid in movement; give celerity to: also used reflexively.
  • To give a certain (specified) speed to; also, to regulate the speed of; arrange for a certain rate of going; set for a determined rapidity.
  • To send off or away; put forth; despatch on a course: as, an arrow sped from the bow.
  • Hence To send or put out of the way; get rid of; send off; do for; in a specific use, to send out of the world; put to death; despatch; kill.
  • To cause to be relieved: only in the passive.
  • To disclose; unfold; explain.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English spede, from Old English spēd, success, swiftness; see spē- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English spede ("prosperity, good luck, quickness, success"), from Old English spēd ("luck, prosperity, success"), from Proto-Germanic *spōdiz (“prosperity, success”), from Proto-Germanic *spōanan (“to prosper, succeed, be happy”), from Proto-Indo-European *spē-, *spʰē- (“to prosper, turn out well”). Cognate with Scots spede, speid ("success, quickness, speed"), Dutch spoed ("haste; speed"), Low German spood ("haste, speed"), German Sput ("progress, acceleration, haste"). Related also to Old English spōwan ("to be successful, succeed"), Albanian shpejt ("to speed, to hurry") and Russian спешить (sp'éšit', "to hurry").

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English speden, from Old English spēdan ("to speed, prosper, succeed, have success"), from Proto-Germanic *spōdijanan (“to succeed”). Cognate with Scots spede, speid ("to meet with success, assist, promote, accomplish, speed"), Dutch spoeden ("to hurry, rush"), Low German spoden, spöden ("to hasten, speed"), German sputen, spuden ("to speed").


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