look up any word, like bae:
 
8.
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
 
9.
A really nasty substance. Like ear wax, saliva, boogers etc.
"Dude! Your ear phones are full of gack!"
by paleteroJ March 27, 2010
 
10.
The first retching sound a cat makes when it hacks up a hairball.
I heard Morris gack after giving himself a tongue bath.
by the_great_waldo October 21, 2009
 
11.
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.
"I did some gack last week and I still feel like shit!"
by PharmaPharmer December 30, 2004
 
12.
Another word for cocaine
Come on lets go and buy a big bag of gack
by tomo April 26, 2004
 
13.
v. - to steal, snatch, grab, or otherwise take something into one's possession
I was thirsty, so I gacked a Coke from his fridge.

If you like the ring, gack it when the clerk turns around.
by BlackArthur January 02, 2004
 
14.
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