fantastic and ballistic are combined together. This refers to when someone gets so excited about something they love, they go ballistic over it! This may include jumping up and down wildly, screaming at the top of ones lungs, hugging everyone in the near vicinity even if they are perfect strangers, pretty much temporary insanity.
The cheerleading team were so excited when they made the final cut at the competition that they went into a fantaballistic fit of simultanious spasms, somewhat like a mosh pit on a trampoline.
by sweetmagnoliya January 03, 2012