Source : Webster's Revised Unabridged Dictionary (1913)

Systematic \Sys`tem*at"ic\, Systematical \Sys`tem*at"ic*al\, a.
   [Gr. ?: cf. F. syst['e]matique.]
   1. Of or pertaining to system; consisting in system;
      methodical; formed with regular connection and adaptation
      or subordination of parts to each other, and to the design
      of the whole; as, a systematic arrangement of plants or
      animals; a systematic course of study.

            Now we deal much in essays, and unreasonably despise
            systematical learning; whereas our fathers had a
            just value for regularity and systems. --I. Watts.

            A representation of phenomena, in order to answer
            the purposes of science, must be systematic.
                                                  --Whewell.

   2. Proceeding according to system, or regular method; as, a
      systematic writer; systematic benevolence.

   3. Pertaining to the system of the world; cosmical.

            These ends may be called cosmical, or systematical.
                                                  --Boyle.

   4. (Med.) Affecting successively the different parts of the
      system or set of nervous fibres; as, systematic
      degeneration.

Source : WordNet®

systematic
     adj 1: characterized by order and planning; "the investigation was
            very systematic"; "a systematic administrator" [ant: {unsystematic}]
     2: not haphazard; "a series of orderly actions at regular
        hours" [syn: {orderly}]