What does the word liturgy mean?
The word "liturgy" originally meant a "public work" or a "service in the name of/on behalf of the people."
In Christian tradition it means the participation of the People of God in "the work of God."
Through the liturgy Christ, our redeemer and high priest, continues the work of our redemption in, with, and through his Church.
Source: Catechism of the Catholic Church (Vatican.va)