Source : Webster's Revised Unabridged Dictionary (1913)

Ideal \I*de"al\, a. [L. idealis: cf. F. id['e]al.]
   1. Existing in idea or thought; conceptional; intellectual;
      mental; as, ideal knowledge.

   2. Reaching an imaginary standard of excellence; fit for a
      model; faultless; as, ideal beauty. --Byron.

            There will always be a wide interval between
            practical and ideal excellence.       --Rambler.

   3. Existing in fancy or imagination only; visionary; unreal.
      ``Planning ideal common wealth.'' --Southey.

   4. Teaching the doctrine of idealism; as, the ideal theory or
      philosophy.

   5. (Math.) Imaginary.

   Syn: Intellectual; mental; visionary; fanciful; imaginary;
        unreal; impracticable; utopian.

Ideal \I*de"al\, n.
   A mental conception regarded as a standard of perfection; a
   model of excellence, beauty, etc.

         The ideal is to be attained by selecting and assembling
         in one whole the beauties and perfections which are
         usually seen in different individuals, excluding
         everything defective or unseemly, so as to form a type
         or model of the species. Thus, the Apollo Belvedere is
         the ideal of the beauty and proportion of the human
         frame.                                   --Fleming.

   {Beau ideal}. See {Beau ideal}.

Source : WordNet®

ideal
     adj 1: conforming to an ultimate standard of perfection or
            excellence; embodying an ideal
     2: constituting or existing only in the form of an idea or
        mental image or conception; "a poem or essay may be
        typical of its period in idea or ideal content"
     3: of or relating to the philosophical doctrine of the reality
        of ideas [syn: {idealistic}]

ideal
     n 1: the idea of something that is perfect; something that one
          hopes to attain
     2: model of excellence or perfection of a kind; one having no
        equal [syn: {paragon}, {nonpareil}, {saint}, {apotheosis},
         {nonesuch}, {nonsuch}]

Source : Free On-Line Dictionary of Computing

IDEAL
     
        1. Ideal DEductive Applicative Language.  A language by Pier
        Bosco and Elio Giovannetti combining {Miranda} and {Prolog}.
        Function definitions can have a {guard} condition (introduced
        by ":-") which is a conjunction of equalities between
        arbitrary terms, including functions.  These guards are solved
        by normal {Prolog} {resolution} and {unification}.  It was
        originally compiled into {C-Prolog} but was eventually to be
        compiled to {K-leaf}.
     
        2. A numerical {constraint} language written by Van Wyk of
        {Stanford} in 1980 for {typesetting} graphics in documents.
        It was inspired partly by {Metafont} and is distributed as
        part of {Troff}.
     
        ["A High-Level Language for Specifying Pictures", C.J. Van
        Wyk, ACM Trans Graphics 1(2):163-182 (Apr 1982)].
     
        (1994-12-15)

ideal
     
         In {domain theory}, a non-empty, {downward closed}
        subset which is also closed under binary {least upper bounds}.
        I.e. anything less than an element is also an element and the
        least upper bound of any two elements is also an element.
     
        (1997-09-26)