Source : Webster's Revised Unabridged Dictionary (1913)

Incognito \In*cog"ni*to\, n.; pl. {Incognitos}. [See
   {Incognito}, a.]
   1. One unknown or in disguise, or under an assumed character
      or name.

   2. The assumption of disguise or of a feigned character; the
      state of being in disguise or not recognized.

            His incognito was endangered.         --Sir W.
                                                  Scott.