Merriam-Webster's Word of the Day for May 17, 2008 is:

incandescent • \in-kun-DESS-unt\  • adjective
1 a : white, glowing, or luminous with intense heat*b : marked by brilliance especially of expressionc : characterized by glowing zeal : ardent 2 a : of, relating to, or being light produced by incandescenceb : producing light by incandescence

Example sentence:
The professor was dazzled by Tia's incandescent prose, which was infinitely more sophisticated than that of the other students in the introductory history course.

Did you know?
"Incandescent" came into the English language toward the end of the 18th century, at a time when scientific experiments involving heat and light were being conducted on an increasingly frequent basis. An object that glowed at a high temperature (such as a piece of coal) was "incandescent." By the mid-1800s, the incandescent lamp -- a.k.a. the "lightbulb" -- had been invented; it contains a filament which gives off light when heated by an electric current. "Incandescent" is the modern offspring of a much older parent, the Latin verb "candēre," meaning "to glow." Centuries earlier, the word for another source of light, "candle," was also derived from "candēre."

*Indicates the sense illustrated in the example sentence.