An adjective meaning something is so great it can only be compared to the amazingness of Ash Ketchum from the original Pokemon series.
Wow, that holographic Charizard limited edition pokemon card is so ash-tastic... I have to get it!
by shawy jill March 07, 2008
something that is over the top amazing.
i went and saw the new twilight it was so ashtastic
by mini-me-94 November 20, 2010