Effulgence derives from the Latin verb fulgēre, which means "to shine." Fulgēre is also the root of fulgent, a synonym of radiant that English speakers have used since the 15th century.

Is effulgence an adjective?

effulgent adjective - Definition, pictures, pronunciation and usage notes | Oxford Advanced Learner's Dictionary at OxfordLearnersDictionaries.com.

What do you mean by effulgence?

Effulgence is brightness taken to the extreme. You may be dazzled by it, stunned by it, or even overcome by it. Usually used to refer to the sun or some other mega-star, effulgence can also be used more figuratively.