Source : Webster's Revised Unabridged Dictionary (1913)

Nameless \Name"less\, a.
   1. Without a name; not having been given a name; as, a
      nameless star. --Waller.

   2. Undistinguished; not noted or famous.

            A nameless dwelling and an unknown name. --Harte.

   3. Not known or mentioned by name; anonymous; as, a nameless
      writer.``Nameless pens.'' --Atterbury.

   4. Unnamable; indescribable; inexpressible.

            But what it is, that is not yet known; what I can
            not name; ?t is nameless woe,I wot.   --Shak.

            I have a nameless horror of the man.  --Hawthorne.

Source : WordNet®

nameless
     adj : being or having an unknown or unnamed source; "a poem by an
           unknown author"; "corporations responsible to nameless
           owners"; "an unnamed donor" [syn: {unidentified}, {unknown},
            {unnamed}]