The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

         Our common forms of compliment are almost all of them
         extravagant hyperboles.                  --Blair.
   [1913 Webster]

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

WordNet (r) 3.0 (2006):

hyperbole
    n 1: extravagant exaggeration [syn: hyperbole, exaggeration]

Moby Thesaurus II by Grady Ward, 1.0:

105 Moby Thesaurus words for "hyperbole":
   abandon, abstractionism, aggrandizement, amplification, ballyhoo,
   big talk, blowing up, boundlessness, burlesque, caricature,
   coloring, deformation, dilatation, dilation, distortion,
   egregiousness, embellishment, enhancement, enlargement,
   enormousness, exaggerating, exaggeration, excess, excessiveness,
   exorbitance, exorbitancy, expansion, expressionism, extravagance,
   extravagancy, extreme, extremes, extremism, extremity,
   fabulousness, false coloring, falsification, garbling, giantism,
   gigantism, gluttony, grandiloquence, heightening, huckstering,
   hyperbolism, hypertrophy, immoderacy, immoderateness, immoderation,
   inaccuracy, incontinence, inflation, injustice, inordinacy,
   inordinance, inordinateness, intemperance, intemperateness,
   litotes, magnification, miscoloring, misdrawing, mispainting,
   misquotation, misreport, misrepresentation, misstatement,
   misteaching, monstrousness, nimiety, nonrealism, outrageousness,
   overdevelopment, overdrawing, overemphasis, overestimation,
   overgreatness, overgrowth, overindulgence, overkill, overlargeness,
   overmuch, overmuchness, overstatement, perversion, prodigality,
   profuseness, puffery, puffing up, radicalism, sensationalism,
   slanting, stretching, superlative, tall talk, too much,
   too-muchness, touting, travesty, twisting, unconscionableness,
   understatement, undueness, unreasonableness, unrestrainedness