The Collaborative International Dictionary of English v.0.48:

Lamentation \Lam`en*ta"tion\, n. [F. lamentation, L.
   lamentatio.]
   1. The act of bewailing; audible expression of sorrow;
      wailing; moaning.
      [1913 Webster]

            In Rama was there a voice heard, lamentation and
            weeping.                              --Matt. ii.
                                                  18.
      [1913 Webster]

   2. pl. (Script.) A book of the Old Testament attributed to
      the prophet Jeremiah, and taking its name from the nature
      of its contents.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lamentation
    n 1: a cry of sorrow and grief; "their pitiful laments could be
         heard throughout the ward" [syn: lament, lamentation,
         plaint, wail]
    2: the passionate and demonstrative activity of expressing grief
       [syn: lamentation, mourning]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "lamentation":
   agony, anguish, bitterness, bleakness, care, carking care,
   cheerlessness, comfortlessness, crying, depression, discomfort,
   dismalness, distress, distressfulness, dreariness, grief, grieving,
   grievousness, heartfelt grief, heartgrief, joylessness,
   lamentability, lamenting, languishment, misery, moaning,
   mournfulness, mourning, pain, painfulness, pathos, pining,
   pitiability, pitiableness, pitifulness, poignancy, prostration,
   regrettableness, sadness, sharpness, sobbing, sorrow,
   sorrowfulness, sorrowing, wailing, weeping, woe, woebegoneness,
   woefulness



Easton's 1897 Bible Dictionary:

Lamentation
   (Heb. qinah), an elegy or dirge. The first example of this form
   of poetry is the lament of David over Saul and Jonathan (2 Sam.
   1:17-27). It was a frequent accompaniment of mourning (Amos
   8:10). In 2 Sam. 3:33, 34 is recorded David's lament over Abner.
   Prophecy sometimes took the form of a lament when it predicted
   calamity (Ezek. 27:2, 32; 28:12; 32:2, 16).