/uy dee"euh liz'euhm/ , n.
1. the cherishing or pursuit of high or noble principles, purposes, goals, etc.
2. the practice of idealizing.
3. something idealized; an ideal representation.
4. Fine Arts. treatment of subject matter in a work of art in which a mental conception of beauty or form is stressed, characterized usually by the selection of particular features of various models and their combination into a whole according to a standard of perfection. Cf. naturalism (def. 2), realism (def. 3a).
5. Philos.
a. any system or theory that maintains that the real is of the nature of thought or that the object of external perception consists of ideas.
b. the tendency to represent things in an ideal form, or as they might or should be rather than as they are, with emphasis on values.
[ 1790-1800; IDEAL + -ISM, prob. modeled on G Idealismus ]