To lay completely rigid, face down on any surface. Your arms must be placed by your side, held straight and fingers pointed. Must also have a expressionless face. Other known as "The Lying Down Game" (UK)
Lets go plank that fence I wanna go planking
By Plankaholic
Sport invented in Australia where you lie flat on your stomach while someone else takes photographs and uploads them onto the internet.
That was some mean planking bro!
By Planker#1
To lie face down with an emotionless face, arms to the side, in a rigid manner. Can be done by anyone on anything to make an impressive picture. It is proper to have a picture taken of oneself planking and post it on Facebook. Originated by British Rugby player David "Wolfman" Williams
Jim- What is that idiot doing laying on the park bench face down looking like a zombie Bob-Ohh he's just planking dude.
By KyleBFC
Lying flat and straight, face down on as small a surface as possible. The weirder or more dangerous the location the better.
Dude 1: Didn't some guy die planking? Dude 2: Yeah, its my new favorite sport!
By letsgoplank
When a person or persons lie flat and rigid face down with both palms pointed down, usually across two surfaces not meant to be lied on. Originating in Australia
Jeff: check out my mad planking skills Frank: dude you just planked across two buses, this is going on facebook
By Jaywalrus