The Collaborative International Dictionary of English v.0.48:

Decompound \De`com*pound"\, v. t. [imp. & p. p. Decompounded;
   p. pr. & vb. n. Decompounding.] [Pref. de- (intens. in
   sense 1) + compound, v. t.]
   1. To compound or mix with that is already compound; to
      compound a second time.
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   2. To reduce to constituent parts; to decompose.
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            It divides and decompounds objects into . . . parts.
                                                  --Hazlitt.
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