Source : Webster's Revised Unabridged Dictionary (1913)

Murk \Murk\, a. [See {Murky}.]
   Dark; murky.

         He can not see through the mantle murk.  --J. R. Drake.

Murk \Murk\, n.
   Darkness; mirk. [Archaic] --Shak.

Murk \Murk\, n.
   The refuse of fruit, after the juice has been expressed;
   marc.

Source : WordNet®

murk
     n : an atmosphere in which visibility is reduced because of a
         cloud of some substance [syn: {fog}, {fogginess}, {murkiness}]
     v : make dark, dim, or gloomy