The act of two people shitting in the same toilet without flushing. (intended as an insult to the bathroom owner)
Hirsch has been an asshole, let's shit stack his toilet.
af acoustic sean 11. april 2008
3 more definitions
A shit large enough for two.
I just pooped a shitstack so high, it's coming out of the bowl.
af daviddeath 21. juni 2014
a pile of shit
Kirby worked up an appetite at the gym so he when he finished he slammed down a shitstack, even eating the curnels of corn. yummmmmm...
af robbbie is funny 29. august 2003
When many males all stack up on the shitter, each sitting on the lap of the person below them. They spread their legs and the shit falls down into the toilet.
paul, steve, mel and andrew shitstacked it together
af SteveB 23. august 2004