any protrusion from a larger body. It could be a topographical feature, as a peninsula, or a small floppy mechanical piece on a machine. A "tag mole" is sometimes referred to as a perdinger. Sometimes it can give a connotation of superfluousness; however, a perdinger could also have great significance depending on its individual nature, placement in the universe, and given characteristics.
"Doctor, if you look closely you will notice the tiny perdinger right next to my left eye. I am worried it might be a cancer."
"How do you turn this thing on?... Flip the little perdinger to the left - you have to reach around for it."
"She lived on that little perdinger part of northern Sardinia in a town called Stintino."
The human appendix is a perfect example of an intestinal perdinger.