1) Anything that happens by chance that is somewhat to extremely mind boggling.
2) Something that occurs that can be described only by few words.
1) "Well all that can be said about that party is that it was absolutely hayness. People everywhere, dude i couldn't tell where the keg was, it was in rotation of rooms."
2) "I have to say, the way that Buster downed that whole bottle of Everclear in all but 30 seconds was hayness."