A foursome. Where as 'hitting a home run' means scoring with one chick, a grand slam means four runs so four chicks.
by matt January 6, 2004
A “Grand Slam” is the act of deficating on the front most edge of a toilet bowl and bringing the lid down to splatter the feces all over the place
by Clarence TCS January 24, 2019
When you go from first base, to second, to third, and to fourth base multiple times throughout the night.
"Dude last night I got a Grand Slam from Ashlee"
"Nice Bro! I would kill to even go to first with her!"
"Nice Bro! I would kill to even go to first with her!"
by TheLoveDrunkPoet June 23, 2012
That wasn't an orgasm, that was a grand slam.
by squirty girl February 19, 2012
To awake one fine morn, and verily discover one's matress resembling a ordinance survey map with a rather warm chocolate log spread all over it as well as spew on your face and pillow.
"I do not think she will want to see me again after I came home totally ringbolted and grand slammed the bed, although your mum is a bit of a dirty slapper."
by Terry Fuckwit June 24, 2004
When you pull your penis as far back between your butt cheeks(chicken in the rough), and put it against a window to surprise someone
by Joe cock February 22, 2017
Rock band former by Phillip Lynott when Thin Lizzy split up. Toured Europe continuously but never recorded anything due to Lynotts untimely death.
Grand Slam bootlegs are very sought after by collectors.
by black flag May 29, 2004