“Alright, alright, counselor, define and describe “The Church” for the benefit of the court reporter and the record, and keep your voice up.”
It is the One, Holy, Catholic and Apostolic Church as in the Orthodox Churches, the Oriental Orthodox Churches and the Church of Rome and those particular churches in communion with it. It is today what was, until the Great Schism and with the exception of the Monophysites, called simply The catholic Church.
There are those who might argue that there are some Lutheran dioceses which would qualify. There used to be some who argued that some dioceses of the Anglican Church also qualified. Whether there still are any or not I don’t know.