1. a group or set of eight things
Usage: formal; rare
2. in ancient Egyptian religion and mythology, a group of eight primordial deities
Usage: historical; religious

Examples

• The ogdoad of Hermopolis was central to Egyptian creation mythology.
• Medieval scholars sometimes organized concepts into an ogdoad for systematic study.
• The eight principles formed an ogdoad of complementary opposites.
• In Gnostic texts, the ogdoad represents the realm of the eight celestial powers.