Complex sentence: "Church" as a synonym, refers to a "particular Christian organization with its own clergy, buildings, and distinctive doctrines"; "church" can also more broadly be defined as the entire body of Christians, the "Christian Church".
Split into simpler sentences: Church as a synonym, refers to a "particular Christian organization with its own clergy, buildings, and distinctive doctrines". Church can also more broadly be defined as the entire body of Christians, the "Christian Church".