JLA: Big doings?

It's been 23 years since DC published Justice League: A Midsummer's Nightmare, and I still have no idea what 'big doings' means, and have never, ever seen it used anywhere else (and I have, sadly, been looking).

I've always suspected the line from Fabian Nicieza, because his New Warriors comics were full of similar weird slang, but this one was not very successful. I certainly haven't been able to get it into a conversation for the past two decades (and I have, sadly, been trying).