from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A metaphysical doctrine denying the existence of matter.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The metaphysical denial of the existence of the material world
from the GNU version of the Collaborative International Dictionary of English
- n. The doctrine that immaterial substances or spiritual being exist, or are possible.
- n. The doctrine that external bodies may be reduced to mind and ideas in a mind; any doctrine opposed to materialism or phenomenalism, esp. a system that maintains the immateriality of the soul; idealism; esp., Bishop Berkeley's theory of idealism.
from The Century Dictionary and Cyclopedia
- n. The doctrine that immaterial substances or spiritual beings exist or are possible.
- n. The doctrine that there is no material world, but that all things exist only in the mind; idealism.
immaterial + -ism (Wiktionary)