Brilliance

google

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late 17th century: from French brillant ‘shining’, present participle of briller, from Italian brillare, probably from Latin beryllus (see beryl).

wiktionary

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Borrowed from French brillance.

etymonline

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brilliance (n.)

"quality of being brilliant," 1755, from brilliant + -ance. Figurative sense (of wit, intelligence, etc.) is from 1779. Distinguished from brilliancy in that the latter usually is applied to things measurable in degrees.