The Collaborative International Dictionary of English v.0.48:

Misname \Mis*name"\, v. t.
   To call by the wrong name; to give a wrong or inappropriate
   name to.
   [1913 Webster]

WordNet (r) 3.0 (2006):

misname
    v 1: assign in incorrect name to; "These misnamed
         philanthropists" [syn: misname, miscall]