The name originated from the Vaticinium, a place where oracles and soothsayers would perform their prophetic rituals in ancient Rome. The area where the Vatican City is located today was originally known as the Ager Vaticanus, and it was associated with these prophetic practices.
However, the word "Vatican" later came to be associated with the Papal Palace, which was built on the site of the ancient Vaticinium. Over time, the name "Vatican" became synonymous with the Papal State, the Catholic Church, and ultimately Vatican City, the independent city-state that is the seat of the Catholic Church.
Therefore, while the root meaning of "Vatican" is "prophecy," its current usage is primarily linked to the Papal authority and Catholicism.