The Collaborative International Dictionary of English v.0.48:

Sorrowful \Sor"row*ful\, a. [OE. sorweful, AS. sorgful.]
   1. Full of sorrow; exhibiting sorrow; sad; dejected;
      distressed. "This sorrowful prisoner." --Chaucer.
      [1913 Webster]

            My soul is exceeding sorrowful, even unto death.
                                                  --Matt. xxvi.
                                                  38.
      [1913 Webster]

   2. Producing sorrow; exciting grief; mournful; lamentable;
      grievous; as, a sorrowful accident.
      [1913 Webster]

   Syn: Sad; mournful; dismal; disconsolate; drear; dreary;
        grievous; lamentable; doleful; distressing.
        [1913 Webster] -- Sor"row*ful*ly, adv. --
        Sor"row*ful*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

sorrowfulness
    n 1: the state of being sad; "she tired of his perpetual
         sadness" [syn: sadness, sorrow, sorrowfulness]
    2: a state of gloomy sorrow [syn: mournfulness,
       sorrowfulness, ruthfulness]