The Collaborative International Dictionary of English v.0.48:

Dusky \Dusk"y\, a.
   1. Partially dark or obscure; not luminous; dusk; as, a dusky
      valley.
      [1913 Webster]

            Through dusky lane and wrangling mart. --Keble.
      [1913 Webster]

   2. Tending to blackness in color; partially black;
      dark-colored; not bright; as, a dusky brown. --Bacon.
      [1913 Webster]

            When Jove in dusky clouds involves the sky.
                                                  --Dryden.
      [1913 Webster]

            The figure of that first ancestor invested by family
            tradition with a dim and dusky grandeur.
                                                  --Hawthorne.
      [1913 Webster]

   3. Gloomy; sad; melancholy.
      [1913 Webster]

            This dusky scene of horror, this melancholy
            prospect.                             --Bentley.
      [1913 Webster]

   4. Intellectually clouded.
      [1913 Webster]

            Though dusky wits dare scorn astrology. --Sir P.
                                                  Sidney.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dusky
    adj 1: lighted by or as if by twilight; "The dusky night rides
           down the sky/And ushers in the morn"-Henry Fielding; "the
           twilight glow of the sky"; "a boat on a twilit river"
           [syn: dusky, twilight(a), twilit]
    2: naturally having skin of a dark color; "a dark-skinned
       beauty"; "gold earrings gleamed against her dusky cheeks"; "a
       smile on his swarthy face"; "`swart' is archaic" [syn: dark-
       skinned, dusky, swart, swarthy]