A slang term used in the drug world meaning the sober person that looks out for the other person who's under the effects of LSD, mushrooms or other hallucinogenic drugs.
You bet I'm gonna try some acid, wanna be my ground control?
by Héctor Andrés Mayoral May 04, 2008
The thing that is to Major Tom.
Ground control to Major Tom.
by cunt roll April 01, 2005