the result of eating fresh out of the oven pizza too fast causing the top layer of skin to burn off of your mouth. Said skin proceeds to fall off of both gums and roof and hang down.
Bagel pizzas are the worst for pizza flap.

LOL! YOU GOT PIZZA FLAP!

dude, my mouth feels like an old ladies flappy face.
by KZB April 3, 2008
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Pizza made of some terrible leftover dough not meant to ever be used in the wonderful art of pizza pies.
"Dude is that Skin-Flap Pizza again?"

"Yeah mom had some leftover Chinese dough, so I thought, why not make a pizza?"

"Disgusting"
by SKinFlap September 12, 2014
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