adj to make acute or witty; to enliven.
2. brighten ·adj to make illustrious, or more distinguished; to add luster or splendor to.
3. brighten ·adj to make bright or brighter; to make to shine; to increase the luster of; to give a brighter hue to.
4. brighten ·vi to grow bright, or more bright; to become less dark or gloomy; to clear up; to become bright or cheerful.
5. brighten ·adj to improve or relieve by dispelling gloom or removing that which obscures and darkens; to shed light upon; to make cheerful; as, to brighten one's prospects.