[circlecity]

"The use of the word "Catholic" was introduced in the fourth century"

What are you talking about? The word catholic is just a translation of the ancient Greek word katholikos (latin: catholicus) which means universal or "according to the whole". It started being used to refer to the Christian church in the second century to emphasize the universal nature of the church. It wasn't until much later that it began being used to describe the Roman Catholic denomination.

[Slyfox]

St. Augustine used it.