noun: An invitation to something where the inviter already knows there's no way the invited can possibly make it. That way he still gets credit for pretending to want to hang out with them.
verb: The act of inviting a person to an event, knowing full well that that can't make it, when you didn't really want them to go anyways.
noun: "Yea, I got the 'unvite' again from Shane. He knows I can't possibly go to Halloween Horror Nights this weekend, what a douche. Then he acts all upset that I can't make it. He's such an ass."
verb: "Philip has to study for a final tonight, so he can't go. Prolly I'll unvite him anyways. That way I still get credit for asking him to hang out"
Sending an invitation very last minute with the hope invitee will already have plans. Unvites are used when you do not want someone to attend but NOT sending them an invitation would be rude.
An Unvite will say something like this:
"Sorry such short notice; I'llunderstand if you can't make it."