An obscure combination of the word sex and dumpling. It is commonly used when an individual is doing unspeakable thinks to bread like products
Eli quit sumping with your roll. People are staring.
by conserned for bread July 04, 2011
1 more definition
The activity of pubescent farmers as their fathers help them wax up their tool.
David was a natural at sumping, his father was delighted, for this meant he no longer needed to sump his own tool.
by ol' Farmer Joe August 09, 2008