Source : Webster's Revised Unabridged Dictionary (1913)

Abstract \Ab"stract`\ (#; 277), a. [L. abstractus, p. p. of
   abstrahere to draw from, separate; ab, abs + trahere to draw.
   See {Trace}.]
   1. Withdraw; separate. [Obs.]

            The more abstract . . . we are from the body.
                                                  --Norris.

   2. Considered apart from any application to a particular
      object; separated from matter; existing in the mind only;
      as, abstract truth, abstract numbers. Hence: ideal;
      abstruse; difficult.

   3. (Logic)
      (a) Expressing a particular property of an object viewed
          apart from the other properties which constitute it;
          -- opposed to {concrete}; as, honesty is an abstract
          word. --J. S. Mill.
      (b) Resulting from the mental faculty of abstraction;
          general as opposed to particular; as, ``reptile'' is
          an abstract or general name. --Locke.

                A concrete name is a name which stands for a
                thing; an abstract name which stands for an
                attribute of a thing. A practice has grown up in
                more modern times, which, if not introduced by
                Locke, has gained currency from his example, of
                applying the expression ``abstract name'' to all
                names which are the result of abstraction and
                generalization, and consequently to all general
                names, instead of confining it to the names of
                attributes.                       --J. S. Mill.

   4. Abstracted; absent in mind. ``Abstract, as in a trance.''
      --Milton.

   {An abstract idea} (Metaph.), an idea separated from a
      complex object, or from other ideas which naturally
      accompany it; as the solidity of marble when contemplated
      apart from its color or figure.

   {Abstract terms}, those which express abstract ideas, as
      beauty, whiteness, roundness, without regarding any object
      in which they exist; or abstract terms are the names of
      orders, genera or species of things, in which there is a
      combination of similar qualities.

   {Abstract numbers} (Math.), numbers used without application
      to things, as 6, 8, 10; but when applied to any thing, as
      6 feet, 10 men, they become concrete.

   {Abstract} or {Pure mathematics}. See {Mathematics}.