If u thinksomeone does something cool or says something or looks cool you can say there Xcore!!! with enthusiasm and you will be the coolest fish in the sea. Trust me i would know.
A suffix that people who want to associate themselves with MTV-fueled facades to make them feel like they are on this earth breathing for some haphazard reason use to create more stupid niches in the teen world.
Add almost any noun or adjective to the beginning of "Xcore", and you've got yourself some individuality. Or not.
That kid is so hardXcore. I heard he started a mosh in the supermarket. That's groceryXcore right there. Damn I am so creative, I just made up another Xcore. Gotta go make a myspace group for it now.