Uranium by product and gouda cheese mixed together to create the one and only gack. Gack has the ability to be a tasty afternoon snack or can also perform shit rockets. shit rockets will expel chunky poo from your bum at speeds exceeding 200 mph, it will, rip your rectum in half.
WOW! I ate gack last night! and it blew my ass in half!
by goo goo the magical elf November 10, 2010
Crank, lower quality methamphetamine not the higher quality crystam version but the stuff that is brown some times and burns like hell. There are 2 types of gack. One eye and two eye. One eye refers to the burning pain and tearing in the eye after snorting. Two eye gack makes both eyes burn and water from snorting it in one nostril.
by PharmaPharmer December 30, 2004
Methamphetamine. Used to describe the gag reflex which can be triggered by the extreme burning sensation of the nasal passages and bitter taste of meth when snorted.
Ever seen the movie, "The Salton Sea"? There's a character called Poo-Bear who snorted so much gack that the doctors had to cut off his nose.
by grandpa July 13, 2003