The Collaborative International Dictionary of English v.0.48:

Obliterate \Ob*lit"er*ate\, v. t. [imp. & p. p. Obliterated;
   p. pr. & vb. n. Obliterating.] [L. obliteratus, p. p. of
   obliterare to obliterate; ob (see Ob-) + litera, littera,
   letter. See Letter.]
   1. To erase or blot out; to efface; to render undecipherable,
      as a writing.
      [1913 Webster]

   2. To wear out; to remove or destroy utterly by any means; to
      render imperceptible; as, to obliterate ideas; to
      obliterate the monuments of antiquity.
      [1913 Webster]

            The harsh and bitter feelings of this or that
            experience are slowly obliterated.    --W. Black.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

obliterated \obliterated\ adj.
   1. destroyed so thoroughly as to be unrecognizable or
      imperceptible.

   Syn: wiped out, obliterate.
        [WordNet 1.5 +PJC]

   2. made illegible or imperceptible by erasing or abrading
      away; -- of writing or surface designs on objects.

   Syn: blotted out, obliterated.
        [PJC]

WordNet (r) 3.0 (2006):

obliterated
    adj 1: reduced to nothingness [syn: blotted out, obliterate,
           obliterated]