Source : Webster's Revised Unabridged Dictionary (1913)

Hyperbole \Hy*per"bo*le\, n. [L., fr. Gr?, prop., an
   overshooting, excess, fr. Gr. ? to throw over or beyond;
   "ype`r over + ? to throw. See {Hyper-}, {Parable}, and cf.
   {Hyperbola}.] (Rhet.)
   A figure of speech in which the expression is an evident
   exaggeration of the meaning intended to be conveyed, or by
   which things are represented as much greater or less, better
   or worse, than they really are; a statement exaggerated
   fancifully, through excitement, or for effect.

         Our common forms of compliment are almost all of them
         extravagant hyperboles.                  --Blair.

         Somebody has said of the boldest figure in rhetoric,
         the hyperbole, that it lies without deceiving.
                                                  --Macaulay.

Source : WordNet®

hyperbole
     n : extravagant exaggeration [syn: {exaggeration}]