The quality or state of shining brightly; brilliance or radiance.
From Latin fulgent- (present participle of fulgēre 'to shine') combined with the suffix -cy, which forms abstract nouns. The Latin root fulgēre likely derives from Proto-Indo-European *bhel- meaning 'to shine or flash.' The term emerged in English in the 17th century to describe luminous or brilliant qualities.
The word fulgency sounds almost like a magic incantation, and that's fitting—it was beloved by Romantic poets trying to capture the supernatural glow of moonlight and stars. It's one of those archaic English words that fell out of fashion when simpler synonyms like 'brilliance' became more popular.
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