A more severe/extreme version of
Down Bad or Down Horrendous. The term is usually used to describe someone who hasn't had a significant other or a hookup in a very long time and is just downright desperate for
literally anyone at this point so that they can experience love, lust, affection, and
everything in between.
Marie: "Hey, isn't this
boy cute?" *Shows picture of HIDEOUS
boy*
Stacie: *Throws up* "Ew Marie! You are definitely down catastrophic!"
Moral of the story is, don't get to a point where you're down catastrophic.