An individual who is heavily under the influence of MDMA (ecstasy, caps, pills, etc.) namely characterised by their dilated pupils and gurning jaw.
by hellohi21 January 19, 2020
Methamphetamine (crank, speed). Describes the gag reflex triggered by the extreme burning sensation of the nasal passages when the drug is snorted, and the very bitter taste as it drains down the back of the throat.
The character 'Pooh-Bear' in the movie "The Salton Sea" had to have his nose surgically removed because he snorted too much gack.
by Anonymous July 14, 2003
by *k!nG Br@nDoN* March 09, 2005
by Orville Blick April 22, 2005
by Theone December 30, 2003
Person: Did you know that Marilyn Manson loves gacking?
Another person: No way!!
Person: Really? Of all the things he's into, THIS, surprises you? Wow. I'm tweeting this convo, ya twat!
Another person: No way!!
Person: Really? Of all the things he's into, THIS, surprises you? Wow. I'm tweeting this convo, ya twat!
by KingFobos March 22, 2016
by mudpup April 05, 2006