1. to reign jointly with another person; to rule together as corulers
Usage: formal; often used in historical or political contexts

Examples

• The two queens agreed to coreign over the kingdom for a period of five years.
• In some constitutional monarchies, a regent may coreign with the reigning monarch.
• The brothers decided to coreign rather than fight for sole control of the territory.
• Historical records show that several Roman emperors chose to coreign with their successors.
• The treaty stipulated that the two nations would coreign the disputed region.