The Collaborative International Dictionary of English v.0.48:

Cheerless \Cheer"less\, a.
   Without joy, gladness, or comfort. -- Cheer"less*ly, adv.
   -- Cheer"less*ness, n.
   [1913 Webster]

         My cheerful day is turned to cheerless night.
                                                  --Spenser.

   Syn: Gloomy; sad; comfortless; dispiriting; disconsolate;
        dejected; melancholy; forlorn.
        [1913 Webster]

WordNet (r) 3.0 (2006):

cheerlessness
    n 1: a feeling of dreary or pessimistic sadness [syn:
         cheerlessness, uncheerfulness] [ant: blitheness,
         cheerfulness]