a condition in which people have a chin and mouth similar to a downs syndrome sufferer but without actually having downs sydrome itself. A fine example of this is the lead singer of the band McFly
"check out the chin on that kid.... that is a serious case of downs chindrome if ever i've seen one"
The art of slapping someone using a "Downs" Hand, thus resulting in the victim having to make you a pie. i.e. an insult
Jake was pissing me off, so i gave him a swift downs slap to his left cheek. He walked straight to the kitchen and immediately started on my banana creme pie.