1. currently ruling or reigning
Usage: formal
2. dominant or prevalent
Usage: formal

Examples

• Queen Elizabeth II was regnant for over seventy years.
• The regnant monarch addressed the nation during the crisis.
• Democratic ideals became regnant in the post-war era.
• The regnant theory in physics was challenged by new discoveries.
• She was the regnant authority on medieval literature.
• The regnant political party faced growing opposition.