luculent

To shed light on the meaning of luculent, one need only look at its root—the Latin noun lux, meaning "light." The English word first appeared in the 15th century with the meaning "brilliant" or "shining," as in "a luculent flame." By the mid-16th century, the "clear in thought or expression" sense had begun to shine, and by that century's end another sense was flickering with the meaning "illustrious" or "resplendent," as in Ben Jonson's 1599 description of a "most debonair and luculent lady." Both the "illustrious" and the "emitting light" senses have fallen out of use, and even the "clear" sense is now rare. Today's writers seem to prefer another lux descendant with a similar meaning: lucid.