1. Noun.  Something that impels, a stimulating factor.
  2. Noun.  A force, either internal or external, that impels; an impulse.
  3. Noun.  The force or energy associated with a moving body; a stimulus.
  4. Noun.  An activity in response to a stimulus.

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This entry was last updated on RefTopia from its source on 3/20/2012.