This describes the large wave that hits your butt when you take a big dump.
When that Big Mac came flying out of my anus like a greased monkey, it made a porcelain tsunami and got poop-water all over my cheeks.
by divinething004 January 19, 2005
1 more definition
Porcelain Tsunami is when your fucking someone in the bathroom from behind near the Toilet and you grab them by the neck or Head and put there head in the toilet and Flush it with there face in it before Busting a Nut.
I just gave her a mean Porcelain Tsunami from the Rear.
by mike mike p. March 20, 2011