gack

The unknown fluid or mass created as a result of decomposition.

Dude, you gotta bury that roadkill. That gack is starting to run down the hill.

by BrightApollo March 7, 2003

Gack

The noise that animate objects make when you sharply grab their neck. Most commonly found in birds and humans.

Father: Go ahead and grab it son.
Son: Ok.
Little Boy: gaaacck
Son: Haha! This is fun.
Little Boy: *gasp* aack gaaah!

by Psionics November 17, 2004

gack

food that sticks to the roof of your mouth, also the process of food getting stickier the more you chew it

"this food is really gacky"

by James 26 December 28, 2005

gacking off

when a guy jacks off without showering for a couple of days (2 OR MORE).

BOB: today i was gacking off

by chivorey March 26, 2009

gack

A man or women's discharge I.E. His or her cum.

I gacked all over her.Or she gacked in my mouth...

by cath boys June 29, 2006

gacking

When your cat gets a random huge energy burst and runs around the house jumping on stuff and knocking things over like a little shit head.

I didn't get much sleep cause my cat was gacking all night.

by Friendlytoad May 19, 2016

Gack Off

Term used to describe when a meth user decides that rather than party with their friends famy and neighbors all weekend, they are going to just irresponsibly spend half their rent money on some dope and go hide out alone in their home and get higher than fuck all weekend...like a speed-driven "METHodical masturbation" type of high...

Bro, I'm so tired of smoking all my dope with these jank-ass chicks around the hood all weekend just to end up not getting any, yet still outta dope by Monday morning....fuck it, time to disappear for a couple days and gack off with my bad self...

by jimjones, omnibeing April 14, 2019