1. A principle or body of principles presented for acceptance or belief, as by a religious, political, scientific, or philosophic group; dogma.
2. A rule or principle of law, especially when established by precedent.
3. A statement of official government policy, especially in foreign affairs and military strategy.
4. Archaic Something taught; a teaching.
[Middle English, from Old French, from Latin doctrīna, from doctor, teacher; see DOCTOR.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.