NOUN (3)

1. a state of great suffering and distress due to adversity;

2. a condition of suffering or distress due to ill health;

3. a cause of great suffering and distress;

The Collaborative International Dictionary of English v.0.48:

Affliction \Af*flic"tion\, n. [F. affliction, L. afflictio, fr.
   affligere.]
   1. The cause of continued pain of body or mind, as sickness,
      losses, etc.; an instance of grievous distress; a pain or
      grief.
      [1913 Webster]

            To repay that money will be a biting affliction.
                                                  --Shak.
      [1913 Webster]

   2. The state of being afflicted; a state of pain, distress,
      or grief.
      [1913 Webster]

            Some virtues are seen only in affliction. --Addison.
      [1913 Webster]

   Syn: Calamity; sorrow; distress; grief; pain; adversity;
        misery; wretchedness; misfortune; trouble; hardship.

   Usage: Affliction, Sorrow, Grief, Distress.
          Affliction and sorrow are terms of wide and general
          application; grief and distress have reference to
          particular cases. Affliction is the stronger term. The
          suffering lies deeper in the soul, and usually arises
          from some powerful cause, such as the loss of what is
          most dear -- friends, health, etc. We do not speak of
          mere sickness or pain as "an affliction," though one
          who suffers from either is said to be afflicted; but
          deprivations of every kind, such as deafness,
          blindness, loss of limbs, etc., are called
          afflictions, showing that term applies particularly to
          prolonged sources of suffering. Sorrow and grief are
          much alike in meaning, but grief is the stronger term
          of the two, usually denoting poignant mental suffering
          for some definite cause, as, grief for the death of a
          dear friend; sorrow is more reflective, and is tinged
          with regret, as, the misconduct of a child is looked
          upon with sorrow. Grief is often violent and
          demonstrative; sorrow deep and brooding. Distress
          implies extreme suffering, either bodily or mental. In
          its higher stages, it denotes pain of a restless,
          agitating kind, and almost always supposes some
          struggle of mind or body. Affliction is allayed, grief
          subsides, sorrow is soothed, distress is mitigated.
          [1913 Webster]

WordNet (r) 3.0 (2006):

affliction
    n 1: a state of great suffering and distress due to adversity
    2: a condition of suffering or distress due to ill health
    3: a cause of great suffering and distress

Moby Thesaurus II by Grady Ward, 1.0:

161 Moby Thesaurus words for "affliction":
   abnormality, acute disease, adverse circumstances, adversity,
   affection, aggravation, ailment, allergic disease, allergy,
   anguish, annoyance, atrophy, bacterial disease, bane, birth defect,
   bitter cup, bitter draft, bitter draught, bitter pill, blight,
   bugbear, bummer, burden, burden of care, calamity, calvary,
   cankerworm of care, cardiovascular disease, care, catastrophe,
   chronic disease, circulatory disease, complaint, complication,
   condition, congenital defect, cross, crown of thorns, crucible,
   crushing burden, curse, death, defect, deficiency disease,
   deformity, degenerative disease, destruction, difficulties,
   difficulty, disability, disaster, disease, disorder, distemper,
   distress, dole, downer, encumbrance, endemic, endemic disease,
   endocrine disease, epidemic disease, evil, functional disease,
   fungus disease, gall, gall and wormwood, gastrointestinal disease,
   genetic disease, grief, grievance, handicap, hard knocks,
   hard life, hard lot, hardcase, hardship, harm, heartache,
   heartbreak, hereditary disease, iatrogenic disease, illness,
   indisposition, infectious disease, infirmity, infliction,
   irritation, load, malady, malaise, mischance, misery, misfortune,
   mishap, morbidity, morbus, muscular disease, nemesis,
   neurological disease, nutritional disease, occupational disease,
   open wound, oppression, ordeal, organic disease, pack of troubles,
   pain, pandemic disease, pathological condition, pathology,
   peck of troubles, pest, pestilence, plague, plant disease, plight,
   predicament, pressure, protozoan disease, psychosomatic disease,
   regret, respiratory disease, rigor, rockiness, rue, running sore,
   scourge, sea of troubles, secondary disease, seediness,
   sickishness, sickness, signs, sorrow, stress, stress of life,
   suffering, symptomatology, symptomology, symptoms, syndrome,
   the pip, thorn, torment, trial, tribulation, trouble, troubles,
   urogenital disease, vale of tears, vexation, vicissitude,
   virus disease, visitation, wasting disease, waters of bitterness,
   weight, woe, worm disease, wretchedness



The Devil's Dictionary (1881-1906):

AFFLICTION, n.  An acclimatizing process preparing the soul for
another and bitter world.