If the word "catholic", from the Greek adjective καθολικός (katholikos), means "universal", why The Catholic Church is known as "The Roman Catholic Church"?
Is it possible be "universal" and "roman" at the same time?
The Catholic Church does indeed usually refer to itself just as "The Catholic Church". That is what it's Wikipedia article calls it (Wikipedia usually names all organizations according to what they call themselves). Many Catholic-related organizations just use the word "Catholic" in their names - CAFOD is an example; Catholic School boards are another.
The term 'Roman Catholic' was originally applied by people who disagree with the Catholic church's claim to be the church (when they were not just referring to it as 'the Roman Church'). Over the centuries the usage has mutated, and term has been applied for various reasons, and is used by many people as if it were the official name of the church. However the history of the usage is extremely complicated. Even the Catholic Church sometimes refers to itself as the "Roman Catholic Church", especially if there is any danger of confusion, or of offence. This Wikipedia article gives some history of the usage of the term Catholic.
Those of you with way too much time on your hands can go and look through the Wikipedia debates on the correct naming of the church in the Catholic Church talk pages.
There are two parts for this:
First part: The Catholic Church ('C' as capital) is that group of churches in communion with the pope. If a group isn’t in communion with the pope, it isn’t part of the Catholic Church.
Within the Catholic Church there are a number of individual churches, sometimes called rites. One of these is the Roman rite or Roman church. It includes most of the Catholics in the Western world. A Roman Catholic is a Catholic who is a member of the Roman rite.
There are many Catholics in the East who are not Roman Catholics, such as Maronite Catholics, Ukrainian Catholics, and Chaldean Catholics. These are all in communion with the pope, but they are not members of the Roman rite, so they are not Roman Catholics.
The Roman rite is not stricter than these other rights. They are equal. They all teach the same faith; it is only local customs that are different among them.
Second part: How the term Roman got attached to it?
It is not possible to give an exact year when the term "Roman Catholic Church," began to be called. The term is assumed to originated as a reference created by Anglicans who wished to refer to themselves as Catholic. They thus coined the term "Roman Catholic" to distinguish those in union with Rome from themselves.
From Catholic Answers: