Getting wasted getting drunk, getting high. My friends and I like throwing up the interlocking arms in the shape of an x whenever we see each other clearly high or plastered.
If someone asked you what's wrong with that really drunk guy in the corner, you would be like that guy is done, he is Xed.
I saw this girl at a rave rubbing her back against the bathroom wall with her eyes wide open while people kept trying to squeeze past her. She was completely Xed out.