Source : Webster's Revised Unabridged Dictionary (1913)

Complication \Com`pli*ca"tion\, n. [L. compliasion: cf. F.
   complication.]
   1. The act or process of complicating; the state of being
      complicated; intricate or confused relation of parts;
      entanglement; complexity.

            A complication of diseases.           --Macaulay.

            Through and beyond these dark complications of the
            present, the New England founders looked to the
            great necessities of future times.    --Palfrey.

   2. (Med.) A disease or diseases, or adventitious
      circumstances or conditions, coexistent with and modifying
      a primary disease, but not necessarily connected with it.

Source : WordNet®

complication
     n 1: the act or process of complicating
     2: a situation or condition that is complex or confused; "her
        coming was a serious complication"
     3: any disease or disorder that occurs during the course of (or
        because of) another disease; "bed sores are a common
        complication in cases of paralysis"
     4: a development that complicates a situation; "the court's
        decision had many unforeseen ramifications" [syn: {ramification}]
     5: puzzling complexity [syn: {complicatedness}, {knottiness}]