[1] : The Collaborative International Dictionary of English v.0.48

decompose \de`compose"\, v. t. imp.  p. p. decomposed; p.
   pr.  vb. n. decomposing. cf. f. d'ecomposer. cf.
   discompose.
   to separate the constituent parts of; to resolve into
   original elements; to set free from previously existing forms
   of chemical combination; to bring to dissolution; to rot or
   decay.
   1913 webster
see also:
decomposed decomposing discompose 

[2] : The Collaborative International Dictionary of English v.0.48

decompose \de`compose"\, v. i.
   to become resolved or returned from existing combinations; to
   undergo dissolution; to decay; to rot.
   1913 webster

[3] : WordNet (r) 2.0

decompose
     v 1: separate substances into constituent elements or parts
          syn: break up, break down
     2: lose a stored charge, magnetic flux, or current; "the
        particles disintegrated during the nuclear fission
        process" syn: disintegrate, decay
     3: break down; "the bodies decomposed in the heat" syn: rot,
         molder, moulder
see also:
break up break down disintegrate decay rot molder 
moulder 

[4] : Moby Thesaurus II by Grady Ward, 1.0

53 moby thesaurus words for "decompose":
   ablate, anatomize, atomize, break down, break up, canker,
   come apart, consume, corrode, corrupt, crack up, crumble,
   crumble into dust, decay, deliquesce, disintegrate, disjoin,
   disorganize, dissect, dissolve, erode, fall into decay,
   fall to pieces, fester, fission, gangrene, go bad, go off,
   go to pieces, liquefy, melt, mildew, mold, molder, mortify,
   moulder, necrose, putrefy, putresce, rankle, resolve, rot,
   separate, sphacelate, split, spoil, suppurate, taint, take apart,
   turn, turn sour, waste away, wear away

Decompose >> D Words
Decompose, definition of term: Decompose
decompose_pag1.html