The Collaborative International Dictionary of English v.0.48:

Detail \De"tail\ (d[=e]"t[=a]l or d[-e]*t[=a]l"; 277), n. [F.
   d['e]tail, fr. d['e]tailler to cut in pieces, tell in detail;
   pref. d['e]- (L. de or dis-) + tailler to cut. See Tailor.]
   1. A minute portion; one of the small parts; a particular; an
      item; -- used chiefly in the plural; as, the details of a
      scheme or transaction.
      [1913 Webster]

            The details of the campaign in Italy. --Motley.
      [1913 Webster]

   2. A narrative which relates minute points; an account which
      dwells on particulars.
      [1913 Webster]

   3. (Mil.) The selection for a particular service of a person
      or a body of men; hence, the person or the body of men so
      selected.
      [1913 Webster]

   4. (Arch. & Mach.)
      (a) A minor part, as, in a building, the cornice, caps of
          the buttresses, capitals of the columns, etc., or
          (called larger details) a porch, a gable with its
          windows, a pavilion, or an attached tower.
      (b) A detail drawing.

   Detail drawing, a drawing of the full size, or on a large
      scale, of some part of a building, machine, etc.

   In detail, in subdivisions; part by part; item by item;
      circumstantially; with particularity.

   Syn: Account; relation; narrative; recital; explanation;
        narration.
        [1913 Webster]

WordNet (r) 3.0 (2006):

in detail
    adv 1: thoroughly (including all important particulars); "he
           studied the snake in detail"

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "in detail":
   accurately, at large, at length, bit by bit, by degrees, by inches,
   by inchmeal, by snatches, completely, concretely, conscientiously,
   definitely, distinctly, drop by drop, especially, exactingly,
   exactly, expressly, exquisitely, foot by foot, fully, fussily,
   in driblets, in extenso, in full, in installments, in lots,
   in particular, in small doses, in snatches, in toto, inch by inch,
   inchmeal, item by item, little by little, meticulously, minutely,
   nicely, part by part, particularly, piece by piece, piecemeal,
   precisely, punctiliously, punctually, refinedly, rigorously,
   scrupulously, separately, singly, specially, specifically,
   strictly, to be specific, wholly, with exactitude,
   with great nicety, with precision