bartleby's WWD today (http://bartleby.com/61/74/F0277400.html):
foudroyant: ADJECTIVE: 1. Dazzling or stunning in effect. ETYMOLOGY: French, from present participle of foudroyer, to strike with lightning
(Honest count: who knew this one before reading this? Not I! )

What a wonderful compliment! "My dear, you look positively foudroyant in that dress tonight."

Perhaps some more words that deserve to be added to our vocabulary of compliment?