Source : Webster's Revised Unabridged Dictionary (1913)

Race \Race\, v. i. [imp. & p. p. {Raced}; p. pr. & vb. n.
   {Racing}.]
   1. To run swiftly; to contend in a race; as, the animals
      raced over the ground; the ships raced from port to port.

   2. (Steam Mach.) To run too fast at times, as a marine engine
      or screw, when the screw is lifted out of water by the
      action of a heavy sea.

Racing \Ra"cing\,
   a. & n. from {Race}, v. t. & i.

   {Racing crab} (Zo["o]l.), an ocypodian.

Source : WordNet®

racing
     n : the sport of engaging in contests of speed