Meaning of THEORY in English

noun the science, as distinguished from the art; as, the theory and practice of medicine.

2. theory ·noun an exposition of the general or abstract principles of any science; as, the theory of music.

3. theory ·noun a doctrine, or scheme of things, which terminates in speculation or contemplation, without a view to practice; hypothesis; speculation.

4. theory ·noun the philosophical explanation of phenomena, either physical or moral; as, lavoisier's theory of combustion; adam smith's theory of moral sentiments.

Webster English vocab.      Английский словарь Webster.