The place on one's person (anus) where you would smuggle items in and out of prison...
my baby's mama was able to sneak me 4 packs of smokes and a connect 4 game pass the gaurds by using her ample sized prison pocket
by jmgiggity September 21, 2011
1. An elusive hiding place used for smuggling illegal substances into "the big house".
"No I don't have any weapons...oh wait.....it's in my prison pocket."
by Garret_ September 17, 2008