ideal

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A conception of something in its absolute perfection.
2. n. One that is regarded as a standard or model of perfection or excellence.
3. n. An ultimate object of endeavor; a goal.
4. n. An honorable or worthy principle or aim.
5. adj. Of, relating to, or embodying an ideal.
6. adj. Conforming to an ultimate form or standard of perfection or excellence.
7. adj. Considered the best of its kind.
8. adj. Completely or highly satisfactory: The location of the new house is ideal.
9. adj. Existing only in the mind; imaginary.
10. adj. Lacking practicality or the possibility of realization.
11. adj. Of, relating to, or consisting of ideas or mental images.
12. adj. Philosophy Existing as an archetype or pattern, especially as a Platonic idea or perception.
13. adj. Philosophy Of or relating to idealism.

Century Dictionary and Cyclopedia

1. Of or pertaining to or consisting in ideas.
2. Existing only in idea; confined to thought or imagination. Not real or practical; imaginary; visionary; incapable of being realized or carried out in fact: as, ideal wealth or happiness; an ideal scheme of benevolence.
3. Conforming completely to a standard of perfection; perfect.
4. In philosophy, regarding ideas as the only real entities; pertaining to or of the nature of idealism.
5. Arising from ideas or conceptions; based upon an ideal or ideals; manifesting or embodying imagination; imaginative: as, the ideal school in art or literature; an ideal statue or portrait.
6. Synonyms Imaginary, fanciful, shadowy, unreal, chimerical.
7. n. That which exists only in idea; a conception that exceeds reality.
8. n. An imaginary object or individual in which an idea is conceived to be completely realized; hence, a standard or model of perfection: as, the ideal of beauty, virtue, etc.; Bayard, the ideal of chivalry.
9. n. A standard of desire; an ultimate object or aim; a mental conception of what is most desirable: as, one's ideal of enjoyment; our ideals are seldom attained.
10. n. Synonyms Pattern, Model, etc. See example.
11. In projective geometry, infinitely distant.
12. n. In mathematics, an ideal number.

Wiktionary

1. adj. Optimal; being the best possibility.
2. adj. Perfect, flawless, having no defects.
3. adj. Pertaining to ideas, or to a given idea.
4. adj. Existing only in the mind; conceptual, imaginary.
5. adj. mathematics Not actually present, but considered as present when limits at infinity are included.
6. n. A perfect standard of beauty, intellect etc., or a standard of excellence to aim at.
7. n. for example, algebra A subring closed under multiplication by its containing ring.

GNU Webster's 1913

1. adj. Existing in idea or thought; conceptional; intellectual; mental.
2. adj. Reaching an imaginary standard of excellence; fit for a model; faultless.
3. adj. Existing in fancy or imagination only; visionary; unreal.
4. adj. Teaching the doctrine of idealism.
5. adj. (Math.) Imaginary.
6. n. A mental conception regarded as a standard of perfection; a model of excellence, beauty, etc.

WordNet 3.0

1. n. model of excellence or perfection of a kind; one having no equal
2. adj. conforming to an ultimate standard of perfection or excellence; embodying an ideal
3. adj. constituting or existing only in the form of idea or mental image or conception
4. adj. of or relating to the philosophical doctrine of the reality of ideas
5. n. the idea of something that is perfect; something that one hopes to attain