1. Given to wit and good humor; merry; sportive; jocular; as, a facetious companion. 2. Characterized by wit and pleasantry; exciting laughter; as, a facetious story or reply.
This is not a word, but a book that you MUST READ if you like words and such. It's called The Professor and the Madman: A Tale of Murder, Insanity and the Making of the Oxford English Dictionary. Written by Simon Winchester. I'm only on the first chapter, and already I love it with a deep passion.