An adjective used to describe something that is spectacular, awesome, cool, or otherwise great to the highest degree. A portmanteau word formed from the words spectacular and yam, the word yamtacular borrows from the greatness of that orange root that tastes so yummy.
Thank you for that yamtacular dinner; it was so good I want to vomit so I can eat some more.
A noun describing a freakishly cool wierdo, very likely a zinester, or someone soon to become a zinester who currently lives in a basement, or lived a large portion of their adolecent lives in a basement.
Anarchy Ashley, maker of the zine 'Alien Basement Food' is a prototypical basement freak.