The Collaborative International Dictionary of English v.0.48:

Misrepresentation \Mis*rep`re*sen*ta"tion\, n.
   Untrue representation; false or incorrect statement or
   account; -- usually unfavorable to the thing represented; as,
   a misrepresentation of a person's motives. --Sydney Smith.
   [1913 Webster]

   Note: In popular use, this word often conveys the idea of
         intentional untruth.
         [1913 Webster]

WordNet (r) 3.0 (2006):

misrepresentation
    n 1: a misleading falsehood [syn: misrepresentation, deceit,
         deception]
    2: a willful perversion of facts [syn: falsification,
       misrepresentation]