Catechism of the Catholic Church §436 — excerpt
The word "Christ" comes from the Greek translation of the Hebrew Messiah, which means "anointed". It became the name proper to Jesus only because he accomplished perfectly the divine mission that "Christ" signifies.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.