noun. A flow of fluid in the opposite direction of its regular flow.

noun. The flow of a fluid (through a pipe etc) in a direction opposite to that which is normal or intended

noun. a flow that returns toward its source

"Joe the Plumber, who found his name repeated again and again by Barack Obama and John McCain during one of the 2008 presidential debates, has somehow bubbled up, like some kind of backflow, into the debate over Proposition B, the ballot measure to bring commonsense standards to large-scale dog breeding operations in the largest of the puppy mill states."

flow  flowing  

regurgitation  

back pressure  closed-center  composted  defrost  derichment  

Charybdis  Maelstrom  back stream  backwash  backwater