Definition of "fulgent"

And univerſally, the greateſt and moſt fulgent tails always ariſe from Comets, immediately after their paſſing by the neighbourhood of the Sun.

1729, Isaac Newton, “Proposition XLI. Problem XXI. From Three Observations Given to Determine the Orbit of a Comet Moving in a Parabola.”, in Andrew Motte, transl., The Mathematical Principles of Natural Philosophy. […] , volume II, London: […] Benjamin Motte, […], book III (Of the System of the World), page 361

Shirley takes life easily: is not that fact written in her eye? In her good-tempered moments, is it not as full of lazy softness as in her brief fits of anger it is fulgent with quick-flashing fire?

1849, Currer Bell [pseudonym; Charlotte Brontë], “Two Lives”, in Shirley. A Tale. […], volume II, London: Smith, Elder and Co., […], page 266