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3.
Common abbreviation of the lovely name 'Celine'. It certainly does not mean any of those other nasty things. :P
Sleen digs the urban dictionary very much.
by Celine aka Sleen July 03, 2006
 
1.
something described as slick and clean at the same time.
"yo man, that ride is sleen" "that's a sleen haircut"
by kocheese May 29, 2006
 
2.
A word with many meanings, can be used as an insult due to it's origin's being a type of Lizard, or alternatively as a way of describing a party/ drinking session.
As an insult/ banter
"What are you, a sailor"
"Filthy slut"
"You're a fucking sleen"

As an adjective
"So, Larry's party tonight in town, all in for a long one?"
"Yeah man, we're gonna get Sleened!"
by HarkinsEgo December 18, 2011
 
4.
v.t. to engage in anal intercourse (contraction of the trade name of petroleum jelly - Vaseline - tm) also sleener
After much pleading, James agreed to allow Patrick to sleen him.
by Harold B. Slusser April 28, 2006