Gack

When you fuck your bitch so hard that her pussy makes a farting sound much like the nickelodeon puddy like material "gack"

Yo dude, last night I gacked the shit out of ashley's pussy.

by ScuryJerry January 20, 2006

gacked

contraction of gobsmacked

I was totally gacked when I saw that pround was a real word.

by Cythere March 3, 2008

gack

The slimy substance (usually green) that was dumped on people in earyl Nickelodeon tv shows

"Thats the incorrect answer so you get drenched by a bucket of gack"

by Cane May 1, 2005

gacked

adj. something that has become so corroded or gummed up with a substance that it is both visbible and fairly disgusting.

The inside of that bowl is so gacked you could sell it.

by aksarah August 24, 2003

Gack

A really nasty substance. Like ear wax, saliva, boogers etc.

"Dude! Your ear phones are full of gack!"

by PaleteroJ March 27, 2010

GACK!

A word or sound muttered/or written by Professors of Anatomy and Physiology when proper terminlogy is not used. Also used un situations of extreme exacerbation.

Student Answer: Gluteus Med.
Professor Commentary on test: GACK! This is not proper terminology.

"GACK!, be quiet now! Or I will leave!"

by Rojay November 30, 2006

gack

Similar to a circus "geek", a "gack" is a circus performer who sucks farts out of chickens.

It was amazing how the circus gack was able to withdraw flatulence from the hens and roosters.

by J.J.W. November 22, 2004