In some religions, a patron saint is a holy figure that protects a place, person, or group. If you lose your keys, try praying to Saint Anthony — the patron saint of lost items.
Roman Catholics and Eastern Orthodox Christians believe that patron saints (who were so virtuous while they were alive that after death they live in heaven and advocate for people with God) offer protection to specific groups. There are patron saints of places (like Joseph, the patron saint of Belgium); of illnesses and problems (Paulina, patron saint of diabetes); and of professions (Dominic, patron saint of astronomers). Patron comes from the Latin patronus, or "protector."