gnip gnop 

Simply put, Ping Pong spelled backwards. Slang and humorous word used instead of "Ping Pong".

Origin: Mansfield University, PA

"You boys up for a game of gnip gnop?"

gnip gnop by Ryan D. Cooper October 7, 2005

gnop-gnip 

Ping-Pong spelled backwards.

This just in: "Ping-Pong" spelled backwards is "Gnop-Gnip".

gnop-gnip by Ashley (Dizzy) January 22, 2008