In Philosophy, Idealism is any theory positing the primacy of Spirit, Mind, or language over matter. It includes claiming that thought has some crucial role in making the world the way it is--that thought and the world are made for one another, or that they make one another. (For example, Immanuel Kant held that the mind forces the world we perceive to take the shape of space-and-time; Georg Hegel thought that history must be rational in something significantly like the way science is.) Finally, "idealism" can denote the belief that abstract or mental entities have some sort of reality "independent" of the world. (Some philosophers think of numbers this way; Plato thought that all properties and objects we could think of must have some such independent existence. Confusingly, this kind of idealism was once termed "Realism".)
Surrealism began as vaguely idealist before tending more towards Materialism.
__Idealism in religious thought__
Not all religion and belief in the supernatural is, strictly speaking, anti-materialist in nature. While many types of religious belief are indeed specifically idealist, for example, Hindu beliefs about the nature of the Brahman, Zen Buddhism stands in the middle way of dialectics between idealism and materialism, and mainstream Christian doctrine affirms the importance of the materiality of Christ's human body and the goodness of the material world.
Several modern religious movements and texts, for example the organizations within the New Thought Movement and the book, A Course in Miracles, may be said to have a particularly idealist orientation. The theology of Christian Science is explicitly idealist.
More accurately Idealism is based on the root word Ideal meaning a perfect form of and is most accurately described as a belief in perfect forms of Virtue, Truth, and The Absolute. Idea-ism would be a more appropriate term for the definitions listed above. There is a clear distinction between an idea and an ideal. i.e. Websters Dictionary says "conforming exactly to an ideal, law, or standard: perfect.
In general parlance, "idealism" or "idealist" is also used to describe a person having high ideals, sometimes with the connotation that those ideals are unrealizable or at odds with "practical" life.Zoom Lebron XIV 14