Dumper Share definition Flag One who dumps, or shits, in someone else's pool or property.Word from Big Black after someone shits in his and robs pool. Some dumper just shit in my poolThere's a shit in the pool... DUMPER Dumper by Tshaw1436 June 20, 2009 0 0 Get merch Get the Dumper mug. Buy Now — $32.95 See more merch