race 2 
(rās)
(rās)n.
1. Sports
a. A competition of speed, as in running or riding.
b. races A series of such competitions held at a specified time on a regular course: a fan of the dog races.
2. An extended competition in which participants struggle like runners to be the winner: the presidential race.
3. Steady or rapid onward movement: the race of time.
4.
a. A strong or swift current of water.
b. The channel of such a current.
c. An artificial channel built to transport water and use its energy. Also called raceway.
5. A groovelike part of a machine in which a moving part slides or rolls.
6. See slipstream.
v. raced, rac·ing, rac·es
v.intr.
1. Sports To compete in a contest of speed.
2. To move rapidly or at top speed: We raced home. My heart was racing with fear.
3. To run too rapidly due to decreased resistance or unnecessary provision of fuel: adjusted the idle to keep the engine from racing.
v.tr.
1. Sports
a. To compete against in a race.
b. To cause to compete in a race: She races horses for a living.
2. To transport rapidly or at top speed; rush: raced the injured motorist to the hospital.
3. To cause (an engine with the gears disengaged, for example) to run swiftly or too swiftly.
[Middle English ras, from Old Norse rās, rush, running; see ers- in the Appendix of Indo-European roots.]