not

Miranda Hobbes: [on the dating scene] There's a lot of push-pull out there, a lot of mixed messages.
Jack Berger: Yeah, I'd have to say that's all code for: He's just not that into you.

A word made popular in the early 90's by the movie Wayne's World. You add "not" to the end of a sentence to make blatant the sarcasm in the sentence itself.
"What a totally amazing, excellent discovery... NOT!!!" -Wayne Campbell
It means "not really" or "we were just kidding".

I got struck by lightning while I was rollerblading today. Not!

A state of being
Coined by Scott Ian of the band Anthrax then later made popular by the movie Wayne's world.
He's a GREAT singer.... NOT!

1> To intend to carry out a task and back out at the last moment.
2> To make a false statement.
James looks like Graham Cash not.

Boolean logic operator that inverts a given value. Often denoted with '~' ('!' in programming languages).
(NOT a) AND (NOT a') = a

A street word referring to Methamphetamines.
Etymology: Called "not" because when you're on Not, you're NOT hungry, NOT sleeping, NOT caring, NOT boring, etc...
Hubbard: Hey, man... what've you got for me?
Stanley: I got not.
Hubbard: Wicked, man. How much?
Stanley: It's all dolla' for dolla' this time.
Hubbard: Sounds great. I'll take 20 cents.

Used to describe an actual state of being.

When someone does something to the extreeme, or does something too much, you -contrary to popular belief- say "not" to describe those actions
-Not Jon Ha is a fag.
-Not Jen got dumped by Jon Ha.
-Not always beating up Jon Ha.