First defined in NASIOC's Off Topic forum by Kaiser as the slow, crampy, painful, and excruciatingly long build-up of poo in one's bowels, which finally reaches a breaking point and results in a massive avalanche of crap being explosively expelled from one's ass. Hence, assalanche.
Zeke sat miserably on the toilet for 30 mins with bad stomach cramps -- a half hour cycle of cramping and loosening and cramping and loosening tearing at his abdomen. But, frustratingly, no poo was shat. He suffered wave after wave of pain...until, finally, that last little snowflake fluttered down on 500 billion tons of brown snow. The assalanche came without warning, and it was fierce. Many people in Toiletville were caught unaware and perished in a 100mph rush of furious poo.
by Zeke Brown May 23, 2007
When an ass is so large that the definition of that ass is completely lost within the body of the individual bearing the ass. Usually best identified when the ass starts amid the fat of the back and ends at or after the knees.
by Jezru December 12, 2007
A massive bowel movement that bowels out of you much the same way an avalanche slides down a mountain destroying everything in its path.
Guy 1: Dude you blew up the toilet, what did you do in there?
Guy 2: It was an assalanche, what can i say?
Guy 2: It was an assalanche, what can i say?
by chumpfong July 15, 2009
by Lucas N. April 26, 2007
Word describing what happened to someone who has a really flat ass. They may have had a nice looking ass at one time, but at some point it evidently broke away and fell off for no apparent reason.
by Dr. Kadiddlehopper February 3, 2010
"I was having such a great day, then it was blotted out by an assalanche streaming down from the manager's conference room. What we in the north country call White Death."
by W2 June 19, 2008
by Feralwinky November 25, 2009