The Collaborative International Dictionary of English v.0.48:

Dissect \Dis*sect"\, v. t. [imp. & p. p. Dissected; p. pr. &
   vb. n. Dissecting.] [L. dissectus, p. p. of dissecare; dis-
   + secare to cut. See Section.]
   1. (Anat.) To divide into separate parts; to cut in pieces;
      to separate and expose the parts of, as an animal or a
      plant, for examination and to show their structure and
      relations; to anatomize.
      [1913 Webster]

   2. To analyze, for the purposes of science or criticism; to
      divide and examine minutely.
      [1913 Webster]

            This paragraph . . . I have dissected for a sample.
                                                  --Atterbury.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dissect
    v 1: cut open or cut apart; "dissect the bodies for analysis"
    2: make a mathematical, chemical, or grammatical analysis of;
       break down into components or essential features; "analyze a
       specimen"; "analyze a sentence"; "analyze a chemical
       compound" [syn: analyze, analyse, break down,
       dissect, take apart] [ant: synthesise, synthesize]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "dissect":
   analyze, anatomize, assay, break down, break up, carve, cleave,
   cut, decompose, dichotomize, disjoin, disjoint, dissever, divide,
   part, penetrate, pierce, probe, reduce, reduce to elements,
   resolve, segment, separate, sever, slice, split, subdivide,
   sunder