Source : Webster's Revised Unabridged Dictionary (1913)

Unconscious \Un*con"scious\, a.
   1. Not conscious; having no consciousness or power of mental
      perception; without cerebral appreciation; hence, not
      knowing or regarding; ignorant; as, an unconscious man.
      --Cowper.

   2. Not known or apprehended by consciousness; as, an
      unconscious cerebration. ``Unconscious causes.''
      --Blackmore.

   3. Having no knowledge by experience; -- followed by of; as,
      a mule unconscious of the yoke. --Pope. --
      {Un*con"scious-ly}, adv. -- {Un*con"scious*ness}, n.

Source : WordNet®

unconscious
     adj 1: not conscious; lacking awareness and the capacity for
            sensory perception as if asleep or dead; "lay
            unconscious on the floor" [ant: {conscious}]
     2: without conscious volition
     3: (followed by `of') not knowing or perceiving; "happily
        unconscious of the new calamity at home"- Charles Dickens
        [syn: {unconscious(p)}]

unconscious
     n : that part of the mind wherein psychic activity takes place
         of which the person is unaware [syn: {unconscious mind}]