Source : Webster's Revised Unabridged Dictionary (1913)

Consciousness \Con"scious*ness\, n.
   1. The state of being conscious; knowledge of one's own
      existence, condition, sensations, mental operations, acts,
      etc.

            Consciousness is thus, on the one hand, the
            recognition by the mind or ``ego'' of its acts and
            affections; -- in other words, the self-affirmation
            that certain modifications are known by me, and that
            these modifications are mine.         --Sir W.
                                                  Hamilton.

   2. Immediate knowledge or perception of the presence of any
      object, state, or sensation. See the Note under
      {Attention}.

            Annihilate the consciousness of the object, you
            annihilate the consciousness of the operation. --Sir
                                                  W. Hamilton.

            And, when the steam Which overflowed the soul had
            passed away, A consciousness remained that it had
            left. . . . images and precious thoughts That shall
            not die, and can not be destroyed.    --Wordsworth.

            The consciousness of wrong brought with it the
            consciousness of weakness.            --Froude.

   3. Feeling, persuasion, or expectation; esp., inward sense of
      guilt or innocence. [R.]

            An honest mind is not in the power of a dishonest:
            to break its peace there must be some guilt or
            consciousness.                        --Pope.

Source : WordNet®

consciousness
     n 1: an alert cognitive state in which you are aware of yourself
          and your situation; "he lost consciousness" [ant: {unconsciousness}]
     2: having knowledge of; "he had no awareness of his mistakes";
        "his sudden consciousness of the problem he faced"; "their
        intelligence and general knowingness was impressive" [syn:
         {awareness}, {cognizance}, {cognisance}, {knowingness}]