Definitions by ROFLCOPTER PERSON FTW

Waterfall 

When you hear a guy pissing in a toilet while he's standing up (Which makes a "waterfall" sound). When you DO hear a waterfall, scream "WATERFALL!!!"

Bob: "Is that your dad pissing?"

Billy: "WATERFALL!"

Waterfall by ROFLCOPTER PERSON FTW October 9, 2011