The Collaborative International Dictionary of English v.0.48:

Masquerade \Mas`quer*ade"\, v. i. [imp. & p. p. Masqueraded;
   p. pr. & vb. n. Masquerading.]
   [1913 Webster]
   1. To assemble in masks; to take part in a masquerade.
      [1913 Webster]

   2. To frolic or disport in disquise; to make a pretentious
      show of being what one is not.
      [1913 Webster]

            A freak took an ass in the head, and he goes into
            the woods, masquerading up and down in a lion's
            skin.                                 --L'Estrange.
      [1913 Webster]