or·tho·dox / ˈôr[unvoicedth]əˌdäks/ • adj. 1. (of a person or their views, esp. religious or political ones, or other beliefs or practices) conforming to what is generally or traditionally accepted as right or true; established and approved: the orthodox economics of today orthodox medical treatment orthodox Hindus. ∎  (of a person) not independent-minded; conventional and unoriginal: a relatively orthodox artist.2. (of a thing) of the ordinary or usual type; normal: they avoided orthodox jazz venues.3. (usu. Orthodox) (of the Jews or Judaism) strictly keeping to traditional doctrine and ritual.4. (usu. Orthodox) of or relating to the Orthodox Church.DERIVATIVES: or·tho·dox·ly adv.

orthodox Orthodox Church a Christian Church or federation of Churches originating in the Greek-speaking Church of the Byzantine Empire, not accepting the authority of the Pope of Rome, and using elaborate and archaic forms of service.

The chief Orthodox Churches (often known collectively as the Eastern Orthodox Church) include the national Churches of Greece, Russia, Bulgaria, Romania, and Serbia. The term is also used by other ancient Churches, mainly of African or Asian origin, e.g. the Coptic, Syrian, and Ethiopian Churches.
Orthodox Judaism a major branch within Judaism which teaches strict adherence to rabbinical interpretation of Jewish law and its traditional observances. There are more than 600 rules governing religious and everyday life. Orthodox Jews maintain the separation of the sexes in synagogue worship.

orthodox according with accepted opinion XVI; spec. epithet of the Eastern Church XVIII. — ecclL. orthodoxus — Gr. orthódoxos, f. orthós straight, right + dóxa opinion, f. base of dokeîn seem, rel. to L. decet (see DECENT).
So orthodoxy XVII. — late L. — late Gr.