Home › Words › O › overbrilliancyoverbrilliancyoverbrilliancy means excessive brilliancy.Among words judged in Lexicurio's Arena, overbrilliancy ranks #16,734 of 42,752 for Qualifying.EtymologyFrom over- + brilliancy.nounExcessive brilliancy.Definitions & examples from Wiktionary (CC BY-SA 3.0).