A tsunami of ass; a VERY large "she" ASS in dynamic motion.
As a big-butted chick (ok, or dude) when she dances the Electric Slide, lookout for the Assnami!!
by Sean & Todd June 25, 2005
When someone with a big ass gets in a pool or body of water and creates a wave that splashes over the side of the walls of said body of water.
I'm sittin by the pool on Saturday when this girl with a huge ass goes in the water and creates this assnami wave that splashes over the side of the pool and got my towell all wet. I hate it when that happens!
by coocoo 4 coco puffs March 20, 2013