The Collaborative International Dictionary of English v.0.48:

Grief \Grief\ (gr[=e]f), n. [OE. grief, gref, OF. grief, gref,
   F. grief, L. gravis heavy; akin to Gr. bary`s, Skr. guru,
   Goth. ka['u]rus. Cf. Barometer, Grave, a., Grieve,
   Gooroo.]
   1. Pain of mind on account of something in the past; mental
      suffering arising from any cause, as misfortune, loss of
      friends, misconduct of one's self or others, etc.; sorrow;
      sadness.
      [1913 Webster]

            The mother was so afflicted at the loss of a fine
            boy, . . . that she died for grief of it. --Addison.
      [1913 Webster]

   2. Cause of sorrow or pain; that which afficts or distresses;
      trial; grievance.
      [1913 Webster]

            Be factious for redress of all these griefs. --Shak.
      [1913 Webster]

   3. Physical pain, or a cause of it; malady. [R.]
      [1913 Webster]

            This grief (cancerous ulcers) hastened the end of
            that famous mathematician, Mr. Harriot. --Wood.
      [1913 Webster]

   To come to grief, to meet with calamity, accident, defeat,
      ruin, etc., causing grief; to turn out badly. [Colloq.]

   Syn: Affiction; sorrow; distress; sadness; trial; grievance.

   Usage: Grief, Sorrow, Sadness. Sorrow is the generic
          term; grief is sorrow for some definite cause -- one
          which commenced, at least, in the past; sadness is
          applied to a permanent mood of the mind. Sorrow is
          transient in many cases; but the grief of a mother for
          the loss of a favorite child too often turns into
          habitual sadness. "Grief is sometimes considered as
          synonymous with sorrow; and in this case we speak of
          the transports of grief. At other times it expresses
          more silent, deep, and painful affections, such as are
          inspired by domestic calamities, particularly by the
          loss of friends and relatives, or by the distress,
          either of body or mind, experienced by those whom we
          love and value." --Cogan. See Affliction.
          [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

153 Moby Thesaurus words for "grief":
   accident, ache, aching, aching heart, adversity, affliction, agony,
   agony of mind, anguish, apologies, attrition, ayenbite of inwit,
   bale, bemoaning, bewailing, bitterness, bleakness, bleeding heart,
   blow, broken heart, burden, calamity, care, carking care, casualty,
   cataclysm, catastrophe, cheerlessness, collision, come apart,
   come to grief, come unstuck, comfortlessness, contretemps,
   contriteness, contrition, crack-up, cramp, crash, crushing, curse,
   cut, dejection, depression, depth of misery, desolation, despair,
   despondency, difficulty, disaster, discomfort, dismalness,
   distress, distressfulness, dole, dolor, dreariness, extremity,
   fail, grievousness, heartache, heartbreak, heartfelt grief,
   heartgrief, heavy heart, hurt, ill hap, infelicity, injury,
   joylessness, lamentability, lamentation, lamenting, languishment,
   lesion, load, melancholia, melancholy, misadventure, miscarry,
   mischance, misery, misfortune, mishap, mournfulness, nasty blow,
   onus, ordeal, pain, painfulness, pang, passion, pathos, pileup,
   pining, pitiability, pitiableness, pitifulness, poignancy,
   prostration, regret, regretfulness, regrets, regrettableness,
   regretting, remorse, remorse of conscience, remorsefulness,
   repining, rue, ruth, sadness, shame, shamefacedness, shamefastness,
   shamefulness, sharpness, shipwreck, shock, smash, smashup, sore,
   sore spot, sorriness, sorrow, sorrowfulness, sorrowing, spasm,
   staggering blow, stress, stress of life, stroke, suffering,
   suicidal despair, tender spot, throes, torment, tragedy, trauma,
   travail, trial, tribulation, trouble, unhappiness, wistfulness,
   woe, woebegoneness, woefulness, worry, wound, wreck, wrench,
   wretchedness