Wikipedia
Serviam is Latin for "I will serve." This was the cry of St. Michael the Archangel as a response to Lucifer's "I will not serve" ( Non serviam) when God put the angels to the test.
Catholics use this term as a prayer which emphasizes their willingness to love and serve God. Catholic bishops, schools, publishers, and institutions have used it as their motto.
Bishops who have used it as their motto are Cardinal Jaime Sin of the Philippines, and Gerard L. Frey, who once headed the dioceses of Savannah, Ga., and Lafayette.1 In honor of Cardinal Sin, the Catholic Mass Media Awards grant a Serviam Award for outstanding service.
The Ursulines Sisters "who opened the first Catholic school in Newham created a school following the "serviam" philosophy of education espoused by the Ursuline foundress, Saint Angela Merici. Her approach to education was simple and yet profound. She encouraged her Sisters to not only teach the required academic subjects and to integrate elements of Catholic faith with the learning process, but she also required her Sisters to integrate service into the learning process. Serviam became a motto for all Ursuline schools and continues as such to this day."2
It is also recommended as a morning prayer or morning offering. The Ursuline prayer is used to ask God to help people show Serviam throughout the day. Serviam is a motto also used in a school called St.Angela's Ursuline, Newham in London. St. Angela's was the first Ursuline school to be opened, which was in 1683. The school is currently an Ursuline school alongside Ilford Ursuline and Wimbledon Ursuline, both also in London.