Source : Webster's Revised Unabridged Dictionary (1913)

Mask \Mask\, v. t. [imp. & p. p. {Masked}; p. pr. & vb. n.
   {Masking}.]
   1. To cover, as the face, by way of concealment or defense
      against injury; to conceal with a mask or visor.

            They must all be masked and vizarded. --Shak.

   2. To disguise; to cover; to hide.

            Masking the business from the common eye. --Shak.

   3. (Mil.)
      (a) To conceal; also, to intervene in the line of.
      (b) To cover or keep in check; as, to mask a body of
          troops or a fortess by a superior force, while some
          hostile evolution is being carried out.

Masked \Masked\, a.
   1. Wearing a mask or masks; characterized by masks;
      cincealed; hidden.

   2. (Bot.) Same as {Personate}.

   3. (Zo["o]l.) Having the anterior part of the head differing
      decidedly in color from the rest of the plumage; -- said
      of birds.

   {Masked ball}, a ball in which the dancers wear masks.

   {Masked battery} (Mil.), a battery so placed as not to be
      seen by an enemy until it opens fire. --H. L. Scott.

   {Masked crab} (Zo["o]l.), a European crab ({Corystes
      cassivelaunus}) with markings on the carapace somewhat
      resembling a human face.

   {Masked pig} (Zo["o]l.), a Japanese domestic hog ({Sus
      pliciceps}). Its face is deeply furrowed.

Source : WordNet®

masked
     adj : having its true character concealed with the intent of
           misleading; "hidden agenda"; "masked threat" [syn: {cloaked},
            {disguised}]