No, it's not a swear word, at least not according to this article on Wired. It actually is a Japanese word that translates (probably very roughly) to "lucky bag." According to the article, the first 200 shoppers to the new Apple store in San Francisco will be able to purchase one of these lucky bags for $250.00 and the bag just might contain a new iPod mini. I guess if you didn't get your name on the pre-order list and you were standing in line long enough to be one of the first 200 people, why not buy the bag? It says in the article that the lucky bag will contain $600-$1000 worth of items -- maybe not such a bad deal (at least in my mind, I already have a 30gb iPod) regardless of whether or not there's an iPod mini in the bag.
Another interesting piece of the article is the link to a video of a near-riot in Japan at a store in Japan who was running the same kind of lucky bag promotion when they opened.
The most interesting piece of the article, this inventory of what was in the lucky bag in Japan:
". . . contained six items, including an iSight camera, a Bluetooth USB adaptor, Bluetooth mouse, Apple's Keynote presentation software, a package for the .Mac online services and a 10 percent discount card for the store."
I sure don't see iPod Mini in the list above, so, personally, if that's what you're buying the bag trying to get (and you're one of the first 200 in line), I would suggest that you just go buy one off the shelf.