Verb: the act of watching a particular series (usually but not always anime) of episodes or movies in a row.
(especially the ENTIRE series at once)
Noun: the series to be watched.
Originated from Eau Claire, Wisconsin. It was created as a more polite/useable form of mindfuck (which means the same thing) by the local university's anime organization. Apparently watching many hours of anime episodes straight does something to you in the head.
Similar to the brainfart, it is the inability to even remember the slightest bit of what you were talking about to the point where someone wonders if you *actually* shit your pants while thinking.
When describing his dog, Rufus had a brainshart and immediately went into a 20 year coma.