Source : Webster's Revised Unabridged Dictionary (1913)

Cimmerian \Cim*me"ri*an\, a. [L. Cimmerius.] [Written also
   {Kimmerian}.]
   1. Pertaining to the Cimmerii, a fabulous people, said to
      have lived, in very ancient times, in profound and
      perpetual darkness.

   2. Without any light; intensely dark.

            In dark Cimmerian desert ever dwell.  --Milton.

Source : WordNet®

Cimmerian
     adj : intensely dark and gloomy as with perpetual darkness; "the
           Cimmerian gloom...a darkness that could be felt"-Norman
           Douglas