imperial ancestral sacrifice

禘 is composed of the radical 示 (shì) and 帝 (dì). 示 is a pictograph of an altar, while 帝 depicts a wooden frame used for fire sacrifices. The original meaning was a ritual involving the burning of wood for worship. As 帝 gradually developed other extended meanings, the character 禘 was created—incorporating the altar radical 示—to specifically retain and express its original sacrificial sense.