Brilliancy

But under all her sparkle there was a strongly felt undercurrent of true, womanly sympathy and kind-heartedness which won affection as easily as her brilliancy won admiration. Nor did she monopolize the conversation. She could draw others out as skillfully and fully as she could talk herself.

[…] to assist greatly in the consumption of the lamp, and to diminish the aqueous precipitations produced on the interior of the lantern glass, which has the effect of reducing more or less the brilliancy of the light.

[H]is ideal of grandeur was a splendid façade, diffusing its brilliancy outward too, irradiating hospitality.

His brilliancy lay in combining old concepts from far-flung fields into a new idea.

Surely it must have been his brilliancy that accounted for Vardon standing out as a stroke or two better than such a model of steadiness as J. H. Taylor[.]

2013, Hannah Eichler, The Key to Brilliancy: How to Unlock Your Child's Genius

Bobby Fischer, one of the greatest chess players who ever lived, died at the age of sixty-four from kidney failure. He had lived one year for each square on a chessboard. / THE GOOD / First of all, you should learn the term “brilliancy.” It refers to a game that is played with spectacular strategy and beauty, typically featuring unexpected moves and ingenious ideas. In other words, the game is extraordinary! At age thirteen, Bobby Fischer won a brilliancy against twenty-six-year-old Donald Byrne.