noun. Breastaciousness beyond belief, like a mega-mammary meltdown.
Real citation: "JT--wow, I don't think I'm quite at AH!'s level of boob-tastic-osity, but thanks a lot!"
(The Cure, Feb. 24, 2005, http://forums.comicbookresources.com/archive/index.php/t-4408-p-3.html)
Made-up citation: "In my house, I was taught to admire tenacity, efficiency, and boob-tastic-osity."