Gack

noun. - Ritalin, Concerta, Vyvance, Adderall, or any other Psycho-Stimulant ADHD Drug.
verb. - the state of mind when on any psychostimulant or adhd drug; usually one listed above

noun - Dude lets buy some Gack tonight.
verb - Dude lets get gacked out.

by ProjectDiesel December 09, 2008