Source : Webster's Revised Unabridged Dictionary (1913)

Synthetic \Syn*thet"ic\, Synthetical \Syn*thet"ic*al\, a. [Gr.
   ?: cf. F. synth['e]tique.]
   1. Of or pertaining to synthesis; consisting in synthesis or
      composition; as, the synthetic method of reasoning, as
      opposed to analytical.

            Philosophers hasten too much from the analytic to
            the synthetic method; that is, they draw general
            conclusions from too small a number of particular
            observations and experiments.         --Bolingbroke.

   2. (Chem.) Artificial. Cf. {Synthesis}, 2.

   3. (Zo["o]l.) Comprising within itself structural or other
      characters which are usually found only in two or more
      diverse groups; -- said of species, genera, and higher
      groups. See the Note under {Comprehensive}, 3.

   {Synthetic}, or {Synthetical language}, an inflectional
      language, or one characterized by grammatical endings; --
      opposed to {analytic language}. --R. Morris.

Synthetic \Syn*thet"ic\, Synthetical \Syn*thet"ic*al\, a. [Gr.
   ?: cf. F. synth['e]tique.]
   1. Of or pertaining to synthesis; consisting in synthesis or
      composition; as, the synthetic method of reasoning, as
      opposed to analytical.

            Philosophers hasten too much from the analytic to
            the synthetic method; that is, they draw general
            conclusions from too small a number of particular
            observations and experiments.         --Bolingbroke.

   2. (Chem.) Artificial. Cf. {Synthesis}, 2.

   3. (Zo["o]l.) Comprising within itself structural or other
      characters which are usually found only in two or more
      diverse groups; -- said of species, genera, and higher
      groups. See the Note under {Comprehensive}, 3.

   {Synthetic}, or {Synthetical language}, an inflectional
      language, or one characterized by grammatical endings; --
      opposed to {analytic language}. --R. Morris.

Source : WordNet®

synthetic
     adj 1: not of natural origin; prepared or made artificially;
            "man-made fibers"; "synthetic leather" [syn: {man-made},
             {semisynthetic}]
     2: involving or of the nature of synthesis (combining separate
        elements to form a coherent whole) as opposed to analysis;
        "limnology is essentially a synthetic science composed of
        elements...that extend well beyond the limits of biology"-
        P.S.Welch [syn: {synthetical}] [ant: {analytic}]
     3: systematic combining of root and modifying elements into
        single words [ant: {analytic}]
     4: of a proposition whose truth value is determined by
        observation or facts; "`all men are arrogant' is a
        synthetic proposition" [syn: {synthetical}] [ant: {analytic}]
     5: artificial as if portrayed in a film; "a novel with flat
        celluloid characters" [syn: {celluloid}]
     6: not genuine or natural; "counterfeit rhetoric that
        flourishes when passions are synthetic"- George Will

synthetic
     n : a compound made artificially by chemical reactions