1. Adhering to the accepted or traditional and established faith, especially in religion.
2. Adhering to the Christian faith as expressed in the early Christian ecumenical creeds.
a. Of or relating to any of the churches or rites of the Eastern Orthodox Church.
b. Of or relating to Orthodox Judaism.
4. Adhering to what is commonly accepted, customary, or traditional: an orthodox view of world affairs.
1. One that is orthodox.
2. Orthodox A member of an Eastern Orthodox church.
[Middle English orthodoxe, from Old French, from Late Latin orthodoxus, from Late Greek orthodoxos : Greek ortho-, ortho- + Greek doxa, opinion (from dokein, to think; see dek- in the Appendix of Indo-European roots).]
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.