look up any word, like blumpkin:
 
1.
Sex with no strings: Casual sex with no expectations of a relationship.
Man looking for SWNS from NE1
by Steve Jacks January 19, 2007
 
2.
swn
smile without noise
everyone lies when they say lol. most of the time there is no laughter involved, so let's be honest, you just smiled.

judy "I slipped on a banana peel today"
john "swn wow, wish i saw"
by Jianna McTyrpick October 12, 2011
 
3.
swn
To "So-own" someones noob ass. Also "Swned". To beat them so badly that a normal "Owned" just won't suffice. Often used in times of great satisfaction and superiority in Online games, namely "Counter-strike"
"John is bringing the swn to those bitch ass chinamen."

"I'm going to Swn those muther fuckers with my AWP"

"Got Swn?"

"I got fuckin swned in the ass"
by rando August 21, 2003