St. Augustine n 1: (Roman Catholic Church) one of the great fathers of the early Christian church; after a dramatic conversion to Christianity he became Bishop of Hippo Regius in North Africa; St. Augustine emphasized man's need for grace (354-430) [syn: {Augustine}, {Saint Augustine}, {Augustine of Hippo}] 2: a resort city in northeastern Florida; the oldest city in the United States [syn: {Saint Augustine}]