Abreviation of 'Penetrate' or 'Penetration,' used specifically in reference to sexual activity.
"I've got a good feeling i'm gonna peno someone tonight."
"Last night I was getting double peno from two guys at once."
An abreviation of the expression 'Room Temperature', meaning plain or neutral. Most commonly used in reference to physical appearance; someone who is neither attractive or unattractive.
"Do I think Lindsay Lohan is hot? Erm... I don't know... maybe. Can't quite decide one way or the other. I'd say she's room."
Used in reference to an attractive woman whom you would be proud to have sex with.
"She's the hottest girl I've ever seen! I'd wash her!"
"That girl I've pulled is so ugly, I wouldn't wash her! But she's easy, and I'm so desperate for sex that I'll probably sleep with her anyway, and then feel really ashamed of myself in the morning."