[1] : The Collaborative International Dictionary of English v.0.48

understatement \un"derstate`ment\, n.
   the act of understating, or the condition of being
   understated; that which is understated; a statement below the
   truth.
   1913 webster

[2] : WordNet (r) 2.0

understatement
     n : a statement that is restrained in ironic contrast to what
         might have been said ant: exaggeration
see also:
exaggeration 

[3] : Moby Thesaurus II by Grady Ward, 1.0

33 moby thesaurus words for "understatement":
   abstractionism, coloring, deformation, distortion, exaggeration,
   expressionism, false coloring, falsification, garbling, hyperbole,
   inaccuracy, injustice, litotes, miscoloring, misdrawing,
   mispainting, misquotation, misreport, misrepresentation,
   misstatement, misteaching, nonrealism, overdrawing, overstatement,
   perversion, quietness, restrainedness, restraint, simplicity,
   slanting, subduedness, twisting, unobtrusiveness

Understatement >> U Words
Understatement, definition of term: Understatement
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