Source : Webster's Revised Unabridged Dictionary (1913)

Dark \Dark\ (d[aum]rk), a. [OE. dark, derk, deork, AS. dearc,
   deorc; cf. Gael. & Ir. dorch, dorcha, dark, black, dusky.]
   1. Destitute, or partially destitute, of light; not
      receiving, reflecting, or radiating light; wholly or
      partially black, or of some deep shade of color; not
      light-colored; as, a dark room; a dark day; dark cloth;
      dark paint; a dark complexion.

            O dark, dark, dark, amid the blaze of noon,
            Irrecoverably dark, total eclipse Without all hope
            of day!                               --Milton.

            In the dark and silent grave.         --Sir W.
                                                  Raleigh.

   2. Not clear to the understanding; not easily seen through;
      obscure; mysterious; hidden.

            The dark problems of existence.       --Shairp.

            What may seem dark at the first, will afterward be
            found more plain.                     --Hooker.

            What's your dark meaning, mouse, of this light word?
                                                  --Shak.

   3. Destitute of knowledge and culture; in moral or
      intellectual darkness; unrefined; ignorant.

            The age wherein he lived was dark, but he Could not
            want light who taught the world to see. --Denhan.

            The tenth century used to be reckoned by medi[ae]val
            historians as the darkest part of this intellectual
            night.                                --Hallam.

   4. Evincing black or foul traits of character; vile; wicked;
      atrocious; as, a dark villain; a dark deed.

            Left him at large to his own dark designs. --Milton.

   5. Foreboding evil; gloomy; jealous; suspicious.

            More dark and dark our woes.          --Shak.

            A deep melancholy took possesion of him, and gave a
            dark tinge to all his views of human nature.
                                                  --Macaulay.

            There is, in every true woman-s heart, a spark of
            heavenly fire, which beams and blazes in the dark
            hour of adversity.                    --W. Irving.

   6. Deprived of sight; blind. [Obs.]

            He was, I think, at this time quite dark, and so had
            been for some years.                  --Evelyn.

   Note: Dark is sometimes used to qualify another adjective;
         as, dark blue, dark green, and sometimes it forms the
         first part of a compound; as, dark-haired, dark-eyed,
         dark-colored, dark-seated, dark-working.

   {A dark horse}, in racing or politics, a horse or a candidate
      whose chances of success are not known, and whose
      capabilities have not been made the subject of general
      comment or of wagers. [Colloq.]

   {Dark house}, {Dark room}, a house or room in which madmen
      were confined. [Obs.] --Shak.

   {Dark lantern}. See {Lantern}. -- The

   {Dark Ages}, a period of stagnation and obscurity in
      literature and art, lasting, according to Hallam, nearly
      1000 years, from about 500 to about 1500 A. D.. See
      {Middle Ages}, under {Middle}.

   {The Dark and Bloody Ground}, a phrase applied to the State
      of Kentucky, and said to be the significance of its name,
      in allusion to the frequent wars that were waged there
      between Indians.

   {The dark day}, a day (May 19, 1780) when a remarkable and
      unexplained darkness extended over all New England.

   {To keep dark}, to reveal nothing. [Low]

Source : WordNet®

Dark Ages
     n : the period of history between classical antiquity and the
         Italian Renaissance [syn: {Middle Ages}]