look up any word, like lemonparty:
 
9.
To reach first base.
Sarah and Jono grinned during the entire movie
by Josh June 05, 2004
 
1.
A smile with an attitude.
I grinned and shot him in the head.
by grin March 05, 2004
 
2.
Slang for marijuana (usually laced). A word used primarily in the West Coast in the 1990's.
See also water or wet.
"I threw away all my grin... and I feel strange..." --Sage

"What's your poison? Grin or gin?" --Carl Johnson

"Man I couldn't find that wet I buried, so I'm making my own. It's easy, fool!" --Ryder

"That ese put dust in my grin."
by 4 LIFE May 24, 2013
 
3.
A play on words of the Pittsburgh expression "Yins" and the bud expression "Greens." Mostly exists to make fun of pitssburghians.
Yo can I get Grins on this bowl?
by Rocky Lebron June 17, 2010
 
4.
an acronym for the set of technologies: genetic, robotic, information & nanotech.

the convergence of theses technologies into a single technology.
investing in GRIN stocks is a sure thing right now.

our children will need access to grintech if they are to compete in a global economy.

GRIN technologies are the modern day 4-horseman of the Apocalypse.
by g.SPIN December 05, 2010
 
5.
when someones pants are not fully up and they bend over and thier bum crack "grins" at you
wow you seem happy today because your certainly grinning at me
by aidyaid87 October 24, 2009
 
6.
smile so sickly sweet it make onlookers through up on site, or passing meat heats punch the grinning idot!
look at the grin on that bloke he looks like hes just got a new girlfriend
by taity July 26, 2006
 
7.
Similar to the old enjoyable verticle smile. It's a hoe's pussy yo!
Gotta love the grin.
by Griz November 16, 2004