- (n.) The science, as distinguished from the art; as, the theory and practice of medicine.
- (n.) A doctrine or scheme of things, which terminates in speculation or contemplation, without a view to practice; hypothesis; speculation.
- (n.) An exposition of the general or abstract principles of any science; as, the theory of music.
- (n.) The philosophical explanation of phenomena, either physical or moral; as, Lavoisier's theory of combustion; Adam Smith's theory of moral sentiments.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). Theory. Retrieved September 21, 2026, from http://smartdefine.org/theory/definitions/2071899 |
| Chicago | Webster's. 2011. "Theory" http://smartdefine.org/theory/definitions/2071899 (accessed September 21, 2026). |
| Harvard | Webster's 2011, Theory, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/theory/definitions/2071899>. |
| MLA | Webster's. "Theory" 28 May 2011. Web. 21 September 2026. <http://smartdefine.org/theory/definitions/2071899> |