Source : Webster's Revised Unabridged Dictionary (1913)

Speed \Speed\, n. [AS. sp?d success, swiftness, from sp?wan to
   succeed; akin to D. spoedd, OHG. spuot success, spuot to
   succees, Skr. sph[=a] to increase, grow fat. [root]170b.]
   1. Prosperity in an undertaking; favorable issue; success.
      ``For common speed.'' --Chaucer.

            O Lord God of my master Abraham, I pray thee, send
            me good speed this day.               --Gen. xxiv.
                                                  12.

   2. The act or state of moving swiftly; swiftness; velocity;
      rapidly; rate of motion; dispatch; as, the speed a horse
      or a vessel.

            Speed, to describe whose swiftness number fails.
                                                  --Milton.

   Note: In kinematics, speedis sometimes used to denote the
         amount of velocity without regard to direction of
         motion, while velocity is not regarded as known unless
         both the direction and the amount are known.

   3. One who, or that which, causes or promotes speed or
      success. [Obs.] ``Hercules be thy speed!'' --Shak.

   {God speed}, Good speed; prosperity. See {Godspeed}.

   {Speed gauge}, {Speed indicator}, & {Speed recorder} (Mach.),
      devices for indicating or recording the rate of a body's
      motion, as the number of revolutions of a shaft in a given
      time.

   {Speed lathe} (Mach.), a power lathe with a rapidly revolving
      spindle, for turning small objects, for polishing, etc.; a
      hand lathe.

   {Speed pulley}, a cone pulley with steps.

   Syn: Haste; swiftness; celerity; quickness; dispatch;
        expedition; hurry; acceleration. See {Haste}.