Source : Webster's Revised Unabridged Dictionary (1913)

Neutral \Neu"tral\, a. [L. neutralis, fr. neuter. See {Neuter}.]
   1. Not engaged on either side; not taking part with or
      assisting either of two or more contending parties;
      neuter; indifferent.

            The heart can not possibly remain neutral, but
            constantly takes part one way or the other.
                                                  --Shaftesbury.

   2. Neither good nor bad; of medium quality; middling; not
      decided or pronounced.

            Some things good, and some things ill, do seem, And
            neutral some, in her fantastic eye.   --Sir J.
                                                  Davies.

   3. (Biol.) Neuter. See {Neuter}, a., 3.

   4. (Chem.) Having neither acid nor basic properties; unable
      to turn red litmus blue or blue litmus red; -- said of
      certain salts or other compounds. Contrasted with {acid},
      and {alkaline}.

   {Neutral axis}, {Neutral surface} (Mech.), that line or
      plane, in a beam under transverse pressure, at which the
      fibers are neither stretched nor compressed, or where the
      longitudinal stress is zero. See {Axis}.

   {Neutral equilibrium} (Mech.), the kind of equilibrium of a
      body so placed that when moved slighty it neither tends to
      return to its former position not depart more widely from
      it, as a perfect sphere or cylinder on a horizontal plane.
      

   {Neutral salt} (Chem.), a salt formed by the complete
      replacement of the hydrogen in an acid or base; in the
      former case by a positive or basic, in the latter by a
      negative or acid, element or radical.

   {Neutral tint}, a bluish gray pigment, used in water colors,
      made by mixing indigo or other blue some warm color. the
      shades vary greatly.

   {Neutral vowel}, the vowel element having an obscure and
      indefinite quality, such as is commonly taken by the vowel
      in many unaccented syllables. It is regarded by some as
      identical with the [u^] in up, and is called also the
      {natural vowel}, as unformed by art and effort. See Guide
      to Pronunciation, [sect] 17.

Neutral \Neu"tral\, n.
   A person or a nation that takes no part in a contest between
   others; one who is neutral.

         The neutral, as far as commerce extends, becomes a
         party in the war.                        --R. G.
                                                  Harper.

Source : WordNet®

neutral
     adj 1: neither moral nor immoral; neither good nor evil, right nor
            wrong
     2: having no personal preference; "impersonal criticism"; "a
        neutral observer" [syn: {impersonal}]
     3: having only a limited ability to react chemically; not
        active; "inert matter"; "an indifferent chemical in a
        reaction" [syn: {inert}, {indifferent}]
     4: not supporting or favoring either side in a war, dispute, or
        contest
     5: having no net electric charge; not electrified [syn: {electroneutral}]
        [ant: {positive}, {negative}]
     6: lacking hue; "neutral colors like back or white"
     7: of no distinctive quality or characteristics or type [ant: {positive},
         {negative}]
     8: lacking distinguishing quality or characteristics; "a
        neutral personality that made no impression whatever"

neutral
     n : one who does not side with any party in a war or dispute