selectively permeable membrane 

A hot girl's vagina.
Very selective on who's dick is permitted through the membrane (her pussy lips.)
Will often deny nervous, non-jock types. The membrane judges largely on physical appearance, not on the pretense of a good personality or wit.

Guy 1- So did you sleep with Elena in the end?
Guy 2- No, she had a selectively permeable membrane.
Guy 1- ... So she turned you down?
Guy 2- Yeah.
Guy 1- Well just say that then!
Guy 2- I needed to make an example for a definition for urban dictionary, okay?!
Guy 1- Oh, right... Wait a minute, am I on TV?!

selectively permeable membrane by uwanttruthitellz May 9, 2009

perved 

drunk and high at the same time

I was tryin to get perved last nite

perved by Lizzie Marie September 1, 2003

permeate

to pass into or through every part of; to penetrate through the pores; to be diffused through; pervade; saturate.

Our thinking is permeated by our historical myths

permeate by Lauren September 29, 2003

perked

Slang for slightly drunk; frequently used in the bay area, equivalent to tipsy

yea, i was a lil perked at the party last night.

perked by jorge199 May 4, 2007

Permadouche 

One who cant be saved or helped from being a douche

I feel kinda sorry for that guy hes in permadouche status.

Permadouche by Realm4227 October 14, 2011

Premeditated Wanking 

Engaging in the act of wanking having pre-planned the desired time, location, and length of time in which the act of wanking should occur. Often used by homosexual men who have other, gayer things they could be doing.

"I prefer premeditated wanking over other types of wanking, I need the time to get ready for something so emotionally affectional"

Premeditated Wanking by nubcake October 16, 2006

perked

drunk from a alcoholic beverage or vicadin

i was so perked last night, i woke up in the gutter of jack in the box

perked by jenn June 30, 2003