The Collaborative International Dictionary of English v.0.48:

Misjudge \Mis*judge"\, v. t. & i.
   To judge erroneously or unjustly; to err in judgment; to
   misconstrue.
   [1913 Webster]

WordNet (r) 3.0 (2006):

misjudge
    v 1: judge incorrectly

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "misjudge":
   contort, distort, err, garble, get one wrong, get wrong, gloss,
   judge amiss, misapply, misappreciate, misapprehend, miscalculate,
   miscite, miscompute, misconceive, misconjecture, misconstrue,
   misdeem, misesteem, misestimate, misevaluate, misexplain,
   misexplicate, misexpound, misinterpret, misquote, misread,
   misreckon, misrender, mistake, misthink, mistranslate,
   misunderstand, misvalue, pervert, squeeze, strain the sense,
   torture, twist the words, wrench