Orthodox Catholic Church vs Eastern Church

Orthodox Catholic Church and Eastern Church both are nouns.

Word	Noun	Adjective	Verb	Adverb
Orthodox Catholic Church	Yes	No	No	No
Eastern Church	Yes	No	No	No

As nouns, Orthodox Catholic Church and Eastern Church are synonyms defined as:

Orthodox Catholic Church and Eastern Church: derived from the Byzantine Church and adhering to Byzantine rites

Other synonyms of Orthodox Catholic Church include Eastern Orthodox, Eastern Orthodox Church, Orthodox Church.

Orthodox Catholic Church (noun)	Eastern Church (noun)
derived from the Byzantine Church and adhering to Byzantine rites	the Catholic Church as it existed in the Byzantine Empire
	derived from the Byzantine Church and adhering to Byzantine rites