Eastern Church and Greek Church

Eastern Church noun - Derived from the Byzantine Church and adhering to Byzantine rites.

Greek Church and Eastern Church are semantically related. In some cases you can replace phrase "Greek Church" with "Eastern Church", this phrases are similar.

Greek Church noun - State church of Greece; an autonomous part of the Eastern Orthodox Church.

Eastern Church and Greek Church are semantically related. You can use "Eastern Church" instead a noun phrase "Greek Church".