Source : Webster's Revised Unabridged Dictionary (1913)

Complicate \Com"pli*cate\, v. t. [imp. & p. p. {Complicated}; p.
   pr. & vb. n. {Complicating}.]
   To fold or twist together; to combine intricately; to make
   complex; to combine or associate so as to make intricate or
   difficult.

         Nor can his complicated sinews fail.     --Young.

         Avarice and luxury very often become one complicated
         principle of action.                     --Addison.

         When the disease is complicated with other diseases.
                                                  --Arbuthnot.

Source : WordNet®

complicated
     adj : difficult to analyze or understand; "a complicated problem";
           "complicated Middle East politics"