Ceres (sîrˈēz) [key], in Roman religion and mythology, goddess of grain; daughter of Saturn and Ops. She was identified by the Romans with the Greek Demeter. Her worship was connected with that of the earth goddess and involved not only fertility rites but also rites for the dead. Her chief festival was the Cerealia, celebrated on Apr. 19, and her most famous cult was that of the temple on the Aventine Hill. There is much argument about the origins and nature of her cults.