Home › Words › U › underglowunderglowunderglow means A glow underneath.Among words judged in Lexicurio's Arena, underglow ranks #3,411 of 42,747 for Qualifying.EtymologyFrom under- + glow.nounA glow underneath.verbTo beam or radiate too little light; to glow insufficiently.Definitions & examples from Wiktionary (CC BY-SA 3.0).