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):

sorrowful
    adj 1: experiencing or marked by or expressing sorrow especially
           that associated with irreparable loss; "sorrowful
           widows"; "a sorrowful tale of death and despair";
           "sorrowful news"; "even in laughter the heart is
           sorrowful"- Proverbs 14:13 [ant: joyful]

Moby Thesaurus II by Grady Ward, 1.0:

96 Moby Thesaurus words for "sorrowful":
   Jeremianic, affecting, afflicted, afflictive, aggrieved, anguished,
   bitter, bleak, blue, careworn, cheerless, comfortless, complaining,
   crestfallen, dejected, deplorable, depressed, depressing,
   depressive, discomforting, disconsolate, disheartened, dismal,
   dismaying, dispirited, distressful, distressing, doleful,
   dolorific, dolorogenic, dolorous, downcast, dreary,
   dumb with grief, faultfinding, fretful, gloomy, grief-stricken,
   griefful, grieved, grievous, hapless, heartsick, howling, in grief,
   in the doldrums, inconsolable, joyless, lamentable, lamentive,
   lugubrious, melancholy, miserable, moanful, mournful, moving,
   painful, pathetic, peevish, petulant, piteous, pitiable, plaintive,
   plangent, plunged in grief, poignant, puling, querulous, regretful,
   regrettable, rueful, ruthful, sad, saddening, sharp, sore,
   sorrow-laden, sorrow-stricken, sorrowed, sorrowing, sorry, tearful,
   touching, troublous, ululant, uncomfortable, unfortunate, unhappy,
   unlucky, wailful, whimpering, whining, whiny, woebegone, woeful,
   wretched