Brilliance comes directly from the English word for radiance, intelligence, or shining excellence.
Brilliance is an English vocabulary name of French and Latin descent, tracing through Old French "brillance" to the Italian "brillare" (to shine, to sparkle) and ultimately to a probable Latin root related to "beryllus" — the gemstone beryl, renowned for its crystalline luminosity. The word entered the English lexicon in the seventeenth century, initially describing the dazzling quality of gems and light, before expanding to describe extraordinary intellectual or artistic gifts.
To call a child Brilliance is to situate her from birth in the language of light and exceptional talent. Word names that denote virtue or aspiration have deep roots in English-speaking cultures — Puritan naming traditions gave us Faith, Hope, Prudence, and Temperance — and the twentieth and twenty-first centuries have expanded this practice toward more grandiose abstractions: Destiny, Serenity, Legacy, and now Brilliance. The name belongs particularly to African American naming traditions, where invented and vocabulary names serve as declarations of worth and future in a culture that has sometimes required its members to assert their humanity loudly and beautifully.
Brilliance as a given name remains genuinely rare, which gives it an arresting quality — it stops people, makes them think, and perhaps encourages the bearer to live into its meaning. It carries a certain weight of expectation, but also an extraordinary generosity: a parent who names a child Brilliance is making a public statement of faith in that child's luminous potential.