1. A state of being that is characteristic of the morning after getting excessively drunk and partying like a rock star. Usually accompanies waking up next to a squaw and/or cha; or waking up alone at 2 in the afternoon with lo mein all over your couch, wing sauce on your sheets, and proceeding to spend the day face down in an US Weekly watching a tv series on DVD. May cause the ordering of a Dominoes pizza.
2. Also, could mean a general decline in status of coolness or random terrible behavior that will inevitably lead to a meltdown.
-Why didn't you go to work yesterday?
-Dude, I was on shamespiral.
-What's up with Jenny (on L-Word)?
-She's got a one way ticket on the shamespiral express to crazy town!