The Collaborative International Dictionary of English v.0.48:

Misinterpret \Mis`in*ter"pret\, v. t.
   To interpret erroneously; to understand or to explain in a
   wrong sense.
   [1913 Webster]

WordNet (r) 3.0 (2006):

misinterpret
    v 1: interpret falsely
    2: interpret wrongly; "I misread Hamlet all my life!" [syn:
       misread, misinterpret]
    3: interpret in the wrong way; "Don't misinterpret my comments
       as criticism"; "She misconstrued my remarks" [syn:
       misconstrue, misinterpret, misconceive,
       misunderstand, misapprehend, be amiss]