Answer
It is called the upper labial frenulum.
The flap of skin attached to the gums and chin inside your mouth is called the frenulum. It helps to connect and stabilize the lips and tongue.
The flap of skin at the elbow is called a wenus.
He had a smiley piercing. That's the flap of skin that holds your upper lip and your gums together.
The flap of skin that shuts off the passage to the lungs is called the epiglottis.
Skin attaches to a muscle called Cuditicial.
it is called a prosterium.
It is called PINNA
a turkey's dewlap is the flap of skin under its neck. Also called a Wattle.
farmers have genetically altered the original perception of turkeys. the reason for this is that the "flap" of skin is edible for human consumption and apparently tastes very nice so the farmers can get even more money for selling that flap of skin
A white skin flap on the side of the tongue is often an inflamed taste bud. The white flap may also be a canker sore.
The gums are the pink skin that the teeth are connected to.
It isn't, except on urban dictionary, and there it seems to be evenly divided between the skin on the inside and outside of the elbow.