I have used the made-up word inciteful a few times. I'd thought I had posted it, but as it didn't turn up in a Search, I reckon I must've sent it in messages. Anyway, I used it as an adjective for a comment that was designed to incite controversy (or perhaps for the person who made it).

If I have to determine what a 'word', pure and simple, is, then I'd have to say any entry that appears in an official dictionary that has a group of experts checking and verifying sources, is a word.

However, I am not against the use of not-officially-recognized terms as words, as long as qualifiers are at least understood, if not stated outright. "Made-up word", "not a real word", etc. I also like tsuwm's term "nonce word".